The immunization of healthcare workers in the early stages of the rollout of COVID-19 vaccines was prioritized in order to ensure uninterrupted medical care provision. At the same time the increasing number of available COVID-19 vaccines may trigger hesitancy towards the decision to get vaccinated. Thus, accumulating reliable information on the adverse events following immunization may educate and urge the general population to receive a COVID-19 vaccine. The present study aimed to evaluate the adverse events (AEs) following immunization with any of the available COVID-19 vaccine among Bulgarian healthcare workers (HCWs). A cross-sectional study among HCWs in Plovdiv, Bulgaria was conducted in the period March – September 2021. Through a semi-structured online questionnaire, the participants reported the adverse events following the administration of the first and second dose of a COVID-19 vaccine. A total of 253 respondents, vaccinated with one of the available vaccines against COVID-19 took part in the study. Of them 71.9% were females, and 75.9% received mRNA-based vaccines, while 24.1% received a viral-vector based vaccine. Overall 91.6% and 82.6% of all participants reported at least one local AE after the first and second dose of a COVID-19 vaccine. The share of respondents reporting at least one systemic AE after the first and second dose of a COVID-19 vaccine was 59.7% and 62.4% respectively. The most common local AE was pain at the injection spot (84.0%), while the most common systemic AEs were fatigue (54.9%), chills (43.2%), and headache (41.7%). The mRNA-based vaccines versions seem to cause higher prevalence of local AEs, while the vector-based vaccines were linked with increased prevalence of systemic AEs. Female HCWs and the younger age group were associated with an increased risk of adverse events generally. Our results added more evidence that mRNA-based and viral-vector based vaccines are generally safe. The reported adverse events were mild, although they occurred in a high share of the respondents. No serious AEs attributable to the vaccines were reported.

We tested the possibility of using “adverse events count” (AEC) as a drug-risk indicator and side-effect severity indicator. Data from 3938 adverse event (AE) reports for COVID-19 vaccines (Comirnaty, Moderna, Vaxzevria, and Janssen) and 6869 AE reports for other medicines were collected from the Bulgarian Drug Agency database (01.01.2018–31.03.2022). AEC was modeled with zero-adjusted negative binomial (ZANBI) and zero-adjusted Poisson inverse Gaussian (ZAPIG) regression models, which account for zero absence and overdispersion. The models’ fit was checked with residual diagnostic plots and parametric correspondence to normality. Explanatory variables were: age, sex, sequence number (order of submission), severity of AE, and vaccine type. Average AEC was higher in severe vs. non-severe AE, and in females vs. males; it decreased with age and was lower in Comirnaty than other vaccines. Variability of AEC for COVID-19 data decreased with sequence number in severe AE and increased in non-severe AE. Full ZANBI models had greater sensitivity than parametric ZANBI or ZAPIG models. Results showed correlation between AEC and AE severity, suggesting AEC as a simple and reliable measure of drug-risk and side-effect severity for clinicians and regulators, especially for COVID-19 vaccines.

Underreporting is the main limitation of the spontaneous reporting systems. This study aims to reduce underreporting enhancing public participation in vaccinovigilance through an SMS-based reporting system integrated with electronic immunization registries (IRs). Using the VigiVax software, parents of vaccinated children aged 2 years or younger received a single SMS inquiry about adverse events following immunization (AEFI). Responses were collected, validated by health operators and integrated with the information on IRs. AEFI reports were automatically submitted to the Italian Pharmacovigilance system. Among 254,160 SMS messages sent, corre-sponding to 451,656 administered doses (AD), 71,643 responses were collected (28.2% response rate), 21,231of them (8.3%) reporting an AEFI. After seriousness assessment based on clinical criteria, 50 reports (0,24%) were classified as serious. Among these, causality assessment identi-fied 31 reports at least potentially related to the vaccination (RR: 6.86/100,000 AD). Febrile seizures following MMRV vaccination accounted for 11 of these 31 cases, with an incidence of 32 per 100,000 AD. No fatal outcomes were reported. Our findings support the highly favorable risk profile of pediatric vaccinations and the possibility to improve spontaneous reporting through the integration of digital technologies.

This paper investigates the safety profile of the Shingrix vaccine, focusing particularly on persistent adverse events post-vaccination. Shingrix, crucial for preventing shingles caused by the varicella-zoster virus, has shown efficacy in clinical trials but is associated with varying degrees of adverse reactions. This retrospective, cross-sectional survey-based study, spanning two years and involving 77 respondents who experienced severe adverse events after vaccination, reveals a spectrum of symptoms ranging from mild to severe, including reports of Guillain-Barré syndrome and neuropathy. These findings underscore the need for ongoing vigilance in vaccine safety monitoring and highlight the importance of personalized care approaches for managing post-vaccination adverse effects. The study aims to contribute to informed decision-making regarding shingles vaccination strategies and calls for continued research into the long-term safety and efficacy of Shingrix.

Background/Objective: Biological females experience more autoimmune disease than males and more treatment-related adverse events (TRAEs) after immune checkpoint blockade therapy. However, little is known about sex-related differences in TRAEs after cancer vaccines. Methods: The Mel44 clinical trial (NCT00118274) enrolled patients with high-risk melanoma to either of two melanoma vaccines. We hypothesized that females would experience higher rates and grades of TRAEs. TRAE rates and grades were compared between sexes, with adjustment for multiple comparisons, and with mixed-effects models. Results: Multiple sex-related differences in TRAE rate and grade were observed in unadjusted comparisons, but only hyperglycemia and hypopigmentation were significantly higher grade by sex after correcting for multiple comparisons: they were increased in males. In mixed-effect mod-els, vaccination strategy, but not patient sex, was independently associated with TRAE rates and grades. Conclusions: These data do not support our hypothesis that TRAEs would be increased in females. Vaccine safety was supported for both males and females.

This study evaluates the incidence and characteristics of adverse events (AEs) following the second COVID-19 booster dose, leveraging Taiwan's distinctive approach of extending booster vaccinations to all citizens, unlike the targeted high-risk group strategies in other countries. Utilizing data from Taipei Veterans General Hospital's Vaccine Adverse Event Reporting System (VAERS) from October 27, 2022, to January 19, 2023, the research examines AEs in 441 out of 1711 second booster recipients, considering factors like age, vaccine brands, and booster combinations. The findings reveal incidence rates (IR) of 25.6% (95% CI: 21.1-30.8) after the first booster and 24.9% (95% CI: 20.5-30.0) after the second, mostly non-serious, with those having AEs post-first booster 5 times more likely to report them again (Incidence rat rato, 5.02, P<0.001). Significantly, switching from the mRNA1273 vaccine to another brand reduced AE risk by 18%. The study underscores that AEs are more repetitive than cumulative with additional booster doses, advocating for personalized vaccination strategies based on individual medical histories and previous vaccine reactions. These insights are valuable for healthcare providers in discussing potential AEs with patients, thereby improving vaccine compliance and public trust, and for policymakers in planning future booster vaccination strategies.

We present a formalism to assess the safety of the COVID19 vaccines and infer a causal relation between vaccine administration and adverse effects, in particular death. We use data on adverse effects from VAERS covering the time interval [01-10-2020, 31-12-2021] (downloaded on 1 Feb 2022). We measure a vaccine fatality rate of order 0.01 for all vaccine manufacturers and identify a strong heterogeneity in the vaccine toxicity across vaccine lots, spanning up to four orders of magnitude. We compute the correlation between vaccination dates and death dates, and produce an estimate of the time lag that maximises the correlation, finding that the onset of adverse effects happened statistically (i.e. 32-41 percentiles) within one day after the vaccine administration and that death happened statistically (i.e. 22-50 percentiles) within about two weeks after the vaccine administration. These results provide data-based insights that can guide public health measures and health insurance policies.

Introduction: Real-world safety studies can provide important evidence on the thromboembolic risk associated with COVID-19 vaccines, considering that millions of people have been already vaccinated against COVID-19. In this study, we aimed to estimate the incidence of thromboembolic events after COVID-19 vaccination and to compare the Oxford–AstraZeneca vaccine with other COVID-19 vaccines. Methods: We conducted a retrospective real-world safety study using data from two different data sources: the Italian Pharmacovigilance database (Rete Nazionale di Farmacovigilanza, RNF) and the Campania Region Health system (Sistema INFOrmativo saNità CampanIA, SINFONIA). From the start date of the COVID-19 vaccination campaign (December 27th, 2021) to September 27th, 2022, information on COVID-19 vaccinations and thromboembolic evets were extracted from the two databases. The reporting rate (RR) and its 95% confidence interval (95%CI) of thromboembolic events for 10,000 doses was calculated for each COVID-19 vaccine. Moreover, the odds of being vaccinated with the Oxford–AstraZeneca vaccine vs. the other COVID-19 vaccines in cases with thromboembolic events vs. controls without thromboembolic events were computed. Results: A total of 12,692,852 vaccine doses were administered in Campania Region, of which 6,509,475 (51.28%) were in female and mostly related to the Pfizer-BioNtech vaccine (65.05%), followed by Moderna (24.31%), Oxford–AstraZeneca (9.71%), Janssen (0.91%), and Novavax (0.02%) vaccines. A total of 641 ICSRs with a COVID-19 vaccines and a vascular events were retrieved from the RNF for the Campania Region, of which 453 (70.67%) were in female. Most ICSRs reported the Pfizer-BioNtech vaccine (65.05%), followed by Oxford–AstraZeneca (9.71%), Moderna (24.31%), and Janssen (0.91%). A total of 2,451 events were reported in the ICSRs (3.8 events for ICSRs) of which 292 were thromboembolic events. The highe RRs of thromboembolic events were found with the Oxford–AstraZeneca vaccine (RR: 4.62, 95%CI: 3.50-5.99) and Janssen vaccine (RR: 3.45, 95%CI: 0.94-8.82). Thromboembolic events were associated with a higher likelihood of exposure to the Oxford–AstraZeneca vaccine compared to Pfizer-BioNtech (OR: 6.06; 95%CI: 4.22-8.68) and Moderna vaccines (OR: 6.46; 95%CI: 4.00-10.80). Conclusion: We observed a higher reporting of thromboembolic events with viral-vector based vaccines (Oxford–AstraZeneca and Janssen) and an increased likelihood of being exposed to the Oxford–AstraZeneca vaccine compared to the mRNA vaccines (Pfizer-BioNtech and Moderna) among thromboembolic cases.

Background: Post-marketing surveillance is crucial for gathering data on vaccine reactogenicity, enhancing public trust in immunization, and promoting vaccine uptake. This study aims to characterize adverse events following immunization (AEFI) and estimate the incidence rates of adverse reactions (ARs) associated with vaccines included in Taiwan's Expanded Program on Immunization (EPI). The study utilizes data from Taiwan's Vaccine Injury Compensation Program (VICP). Methods: Vaccine injury claims submitted to the VICP between 2014 and 2019 were analyzed. ARs were defined as AEFIs adjudicated as ‘related’ or ‘indeterminate’ by the VICP committee. Data on the annual number of vaccine doses administered was obtained from the Taiwan CDC, which helped calculate AR incidence rates. Results: A total of 491 AEFI claims were reviewed, with 327 (66.6%) categorized as ARs. AEFIs were mainly associated with the Bacillus Calmette-Guérin (BCG) vaccine (43.4%) and the seasonal influenza vaccine (22.0%). Most EPI vaccines demonstrated low AR incidence rates, ranging from 1.68 to 13.6 per million doses, with the exception of BCG, which exhibited 162.5 ARs per million doses. Shifting BCG immunization from below 5 months to at least 5 months reduced osteomyelitis incidence significantly, from 41.4 to 7.9 (P = 0.0014), but increased abscess and lymphadenitis cases. Conclusion: EPI vaccines in Taiwan are highly safe, with minimal AR incidences in the general population. The BCG vaccine remains an exception, occasionally causing severe ARs like osteomyelitis. Adjusting the immunization schedule to an older age may mitigate some of these adverse effects.

The intricate mechanisms of the immune response elicited by vaccines and the interplay between the immune system and the central nervous system (CNS) are poorly understood. This review explores these mechanisms, emphasizing the interplay between the immune system and the central nervous system (CNS). A critical aspect is the examination of how vaccine-induced immune responses can interact with the CNS, influencing neuroinflammation and neuroimmune interactions. Furthermore, the link between vaccination and persistent symptoms observed in long-COVID patients is discussed. Vaccination initiates a complex cascade of events, starting with the production of specific proteins, such as S1/S2 spike proteins, leading to robust immune activation in the axillary lymph nodes. The role of macrophages and antigen-presenting cells (APCs) in cytokine production, antigen presentation, and the stimulation of B and T cells highlights the sophistication of the adaptive immune response. The migration of immune cell-derived exosomes to the brain plays a dynamic role in CNS inflammation, neurodegenerative processes and long COVID. On the other hand, the prolonged presence of viral and vaccine-derived spike proteins may contribute to the complex pathophysiology of Long-COVID, shedding light on the delicate balance between beneficial immune responses and possible adverse neurological outcomes of vaccination. It is worth rigorous monitoring and further research to understand the mechanisms of neuroinflammation and the persistence of spike proteins and their long-term effects on the brain, emphasising the importance of a nuanced approach to vaccine safety and efficacy in the context of COVID-19 and beyond.Principio del formulario

Background: Vaccination is one of the most effective life-saving medical interventions, and the introduction of SARS-CoV-2 vaccines was intended to prevent the serious implications of COVID-19. The objectives of the study were: i) to observe the humoral immune response to BNT162b2 vaccine and SARS-CoV-2 infection (mainly breakthrough infections), ii) to demonstrate the persistence of anti-SARS-CoV-2 antibodies over time in relation to the number of received vaccine doses and the course of infection, and iii) to determine adverse effects after primary vaccine doses. Methods: To assess the humoral response, IgG and IgA anti-S1 antibodies were quantified by ELISA assays. In total, the tests were carried out seven times in almost two years. Results: We demonstrated strong immunogenicity (compared to levels before primary vaccination, 150- and 20-fold increases in IgG and IgA, respectively) of the BNT162b2 vaccine. Over time, we observed a systematic decline in antibody levels, which may have contributed to breakthrough infections. Although they caused seroconversion similar to the booster, antibody levels in such patients fell more rapidly than after re-vaccination. On the other hand, in individuals who did not receive booster(s) and who did not present breakthrough infection, anti-SARS-CoV-2 antibodies returned to pre-vaccination levels after 20 months. The most commonly recognized adverse effects were injection site redness and swelling. Conclusion: Vaccination is highly effective in preventing the most severe outcomes of COVID-19 and should be performed regardless of prior infection. Booster doses significantly enhance anti-SARS-CoV-2 antibody levels and, in contrast to those obtained by breakthrough infection, they remain longer.

Gardasil 4, a human papilloma virus vaccine, has been shown to protect against various cancers, including cervical cancer. Common side effects include injection site pain, fever, headaches, and muscle aches. In some individuals, the severe side effect of postural orthostatic tachycardia syndrome (POTS) has been reported. POTS is characterized by the abnormal response of lightheadedness, blurry vision, and dizziness while transitioning to an upright posture. POTS predominately affects women, with more than eighty-five (85) percent of POTS patients being female. POTS on average, takes five years and eleven months to receive the diagnosis. Additionally, ​A strong association between POTS and Ehlers Danlos Syndrome Type III (EDS) exists. Eighty (80) percent of patients with EDS have POTS. This severe side effect dictates that providers need to be aware of this strong association of HPV vaccinations and POTS. ​In this report we will present a case of a young women with a past medical history significant for EDS type III who was diagnosed with POTS after receiving Gardasil 4 vaccination. This case demonstrates the need for physicians to be aware of the association of POTS with EDS type III and HPV vaccination. Physician awareness of the associations, signs and symptoms of POTS and earlier testing at the first presentation of signs and symptoms will limit the negative impact on patient’s quality of life.

Human papillomavirus (HPV) infection is a widespread sexually transmitted infection linked to various types of cancers. Although vaccination against HPV is available, global HPV vaccination rates remain low. This study aimed to evaluate the awareness and knowledge of the HPV vaccine and to identify predictors associated with vaccine hesitancy among health college students in Saudi Arabia. A cross-sectional survey was distributed to students enrolled in health colleges. The association of vaccine hesitancy with sociodemographic characteristics was examined using logistic regression analysis. The study found that approximately half of the students (49.9%) were aware of the HPV vaccine. Students from the College of Medicine showed the highest level of knowledge. Only a small proportion (5.2%) reported receiving the vaccine. The overall HPV vaccine hesitancy was 59.1% (43.9% for women and 75.9% for men). The most common reasons for vaccine hesitancy was not knowing enough about it. Men were twice as likely as women to believe that they did not need the HPV vaccine. The odds for HPV vaccine hesitancy were greater among men and younger age group compared to women and older age group. In conclusion, the study underscores the importance of awareness campaigns on HPV vaccination, targeting primarily male students.

We revisit a 2023 JAMA-published analysis of data from patients admitted for either COVID-19 or influenza to U.S. Veterans Administration (VA) hospitals in the fall/winter of 2022-2023. We note that baseline characteristics between the cohorts were similar, and the difference in vaccination rates was minimal, even after propensity score weighting. Had the vaccines been even minimally effective, significant differences in vaccination percentages would be expected. These findings call into question any efficacy claims associated with either the COVID-19 or influenza vaccines. Furthermore, the lack of efficacy of the influenza vaccines in reducing hospitalization is consistent with an earlier detailed study that found the same lack of efficacy, further validating the current result. This suggests that comparing vaccination rates between those hospitalized for different vaccine-preventable diseases can serve as a practical method for validating the vaccine efficacy claims of different vaccines.

Vaccination is one of the most effective methods for preventing morbidity and mortality from COVID-19. Vaccine hesitancy has led to a decrease in vaccine uptake; driven by misinformation, fear, and perceptions of vaccine safety. Whole inactivated vaccines have been used in one-fifth of the vaccine recipients in Africa, however there is limited real-world data on their safety. We evaluated the reported side effects and factors associated with reported side effects following vaccination with whole inactivated COVID-19 vaccines - BBiBP-CorV (Sinopharm) and CoronaVac (Sinovac). A quantitative survey evaluating attitudes and side effects from vaccination was administered to 1016 adults presenting at vaccination centers. Two follow-up telephone interviews were conducted to determine side effects after the first and second vaccination dose. Overall, the vaccine was well tolerated; 26.0% and 14.4% reported side effects after the first and second dose respectively. The most frequent local and systemic side effects were pain at the injection site and headaches respectively. Most symptoms were mild, and no participants re-quired hospitalization. Participants who perceived COVID-19 vaccines as safe or had a personal COVID-19 experience were significantly less likely to report side effects. Our findings provide data on the safety and tolerability of whole inactivated COVID-19 vaccines in an African population, providing the necessary data to create effective strategies to increase vaccination and support vaccination campaigns.

Parental refusal of childhood vaccines is a growing public health concern. Numerous reasons exist for this refusal, including religious, personal, and philosophical beliefs, and safety concerns. However, parental refusal of childhood vaccines is not simply an individualized problem for the family; this impacts herd immunity and affects the entire community. To improve vaccination rates among the pediatric population, understanding the thought process and decision-making behind parental opposition and refusal of vaccinations is essential. Using a survey developed to assess attitudes towards recommended childhood vaccines and the COVID-19 vaccine, this study examined the correlation between vaccine literacy and hesitancy among parents and legal guardians of elementary school-aged children in the Midwest. Responses were analyzed using Chi-squared tests on “R” software. Significant negative correlations were found between COVID-19 hesitancy and vaccine literacy, and resistance towards all vaccines and vaccine literacy. No significant negative correlations were found between hesitancy towards all vaccines and vaccine literacy, or hesitancy and literacy among different income and education brackets. Our results suggest that vaccine education may lessen vaccine hesitancy among parents and may be an essential factor in improving vaccination rates among the pediatric population.

The reason for this dissertation is to establish the effects of vaccination on the elderly (>65 years old) in Hong Kong in reducing flu infection. Influenza vaccine uptake in the elderly (˃65 years old) in Hong Kong significantly increased in 2003 after the SARS epidemic. The exact impacts of influenza vaccine among the elderly in Hong Kong are a subject of contention. The effectiveness of the influenza vaccine comes from observed studies which may be prejudiced since it is difficult to identify and justify the evidence. A review of various literatures has shown that influenza causes serious illness and death particularly highly vulnerable groups such as adults aged 65 years and above. Therefore, more efforts should be initiated to reduce mortality caused by influenza among the elderly. According to the WHO (2005), vaccination is among the most effective approach for preventing death associated with influenza to vulnerable groups such as the elderly.

Understanding vaccine hesitancy in organ transplant recipients (OTR) is critical, given clear, alt-hough attenuated, benefits from vaccination. Adult OTR were surveyed regarding vaccine-related values and a novel outcome variable called Vaccine Acceptance Composite Score (VACS) was built as the average Likert score of 7 domains of vaccination confidence. Of 46 OTR included (93.5% kidney transplant recipients), 32.6% were female, 13.3% Black, 6.77% Hispan-ic/Latino/a/x; median age was 58 years. Patients were most concerned about COVID-19 vac-cine-associated risks (46.3%), its potential effect on allograft (47.6%) and motives of government officials involved with vaccine policy (55.6%). Politically conservative patients were likely to have a significantly lower VACS, while those who lived with someone ≥65 had a higher VACS. The VACS was not significantly associated with race, income, religious beliefs, comorbidities, COVID-19 history, or influenza vaccination status. Higher VACS was significantly associated with ≥3 and ≥4 COVID-19 immunizations. This study highlighted political beliefs and elderly household members as correlates of vaccine acceptance among OTR. The VACS may be a useful tool to help standardize multifaceted analyses in vaccination-focused behavioral research, as well as identify individuals and groups at risk for vaccine hesitancy, who may benefit from tai-lored outreach and educational interventions.

Unprecedented in scale, immense COVID-19 immunization programmes have been rolled out globally. This article explores aspects of hypothetical vaccine acceptability in Soweto, South Africa, shortly before such vaccines became available. Whereas hypothetical acceptance was normative, this has not translated into uptake today, which remains concerningly low in South Africa, especially in Soweto. For that reason, we mobilise anthropological concepts to analyse acceptance, hesitancy, and denial, respectively, to gauge and understand public proclivity to inoculate. We find that COVID-19’s haphazard mediatization generated a ‘field of suspicion’ towards authorities and vaccination, which, amplified by dis- and misinformation, fostered othering, hesitancy, and denial considerably. It remains paramount during vaccination rollouts to unveil and address aspects detrimental to vaccine confidence and selectivity, especially in lower-income groups for underlying, context-specific cultural, spiritual, historical, and socioeconomic reasons. Appropriate mediazation alongside a debunking of counterfactual claims is crucial in driving forward immunization.

Vaccine uptake is one of the indicators that has been used to guide immunization programs. This study aimed to evaluate whether the measles vaccine uptake is predicted by measles vaccine hesitancy. A community-based cross-sectional study was conducted in urban districts in Khartoum state in February 2019. Measles vaccine uptake among children was measured as either fully vaccinated or partially/not vaccinated. The Parents Attitude about Childhood Vaccination (PACV) scale was used to measure measles vaccine hesitancy. Multivariate logistic regression was run to identify the predictors of measles vaccination uptake controlling for sociodemographic variables and the adjusted odds ratios (aORs) with 95% CI were calculated. The receiver operator characteristic (ROC) curve was performed, besides area under the curve (AUC) for the PACV was computed. Data was collected from 495 participants. We found that measles vaccine hesitancy (PACV scores) predicted the uptake of measles vaccine after controlling other potential social confounders such as mother’s age and the number of children (aOR 1.055, 95% CI 1.028-1.028). Additionally, the ROC for the PACV yielded area under the curve (AUC 0.686 (95% CI 0.620-0.751, P <0.001). Our findings show that measles vaccine hesitancy in Sudan directly influences the uptake of the measles vaccine. Addressing the determinants of vaccine hesitancy through communication strategies will improve vaccine uptake.

In this study, we surveyed over 600 participants to determine: a) major causes to mental stress during the pandemic and its future impacts, and b) diversity in public perception and acceptance (specifically for children) of Covid-19 vaccination. Statistical results and intelligent clustering outcomes indicate significant relationships between sociodemographic diversity, mental stress causes, vaccination perception, and Covid-19 infections. For instance, statistical results indicate significant dependence between mental stress due to Covid-19 and gender (p = 1.7e-05). Over 25% of males indicated work related stress comparing 35% in females however, females indicated more stressed (17%) due to relationships comparing to males (12%). Around 30% of Asian/Arabic participants don’t feel vaccination being safe as compared to 8% of white-British and 22% of white-European indicating significant dependence (p = 1.8e-08) with ethnicity. More specifically, vaccination acceptance for children is significantly dependent to ethnicity (p = 3.7e-05) where only 47% participants show willingness towards children’s vaccination. Primary dataset in this study along with experimental outcomes identifying sociodemographic information diversity with respect to public perception and acceptance of vaccination to children and potential stress factors might be useful for public and policy makers to be better prepared for future epidemics as well as working globally to combat mental health issues and running more effective vaccination campaigns.

Early experience with Covid-19 shows that vaccines can be the most effective way of preventing the spread of infection. However, vaccine hesitancy is among the most significant hurdles in preventing the spread of novel infections. Monkeypox (MPX) has already been declared a global health emergency by WHO. Thus, there is an urgent need to understand the MPX vaccine willingness in various population groups. In this cross-sectional study, an online survey was conducted among Saudi healthcare workers (HCWs) to understand the monkeypox vaccine willingness in healthcare workers in Saudi Arabia. Saudi has already confirmed multiple MPX cases, and thus it is essential to initiate timely protective measures, including vaccination. The study had 743 respondents. The study found that among Saudi HCWs, 52.7% were willing to receive the MPX vaccine. The study found that sociodemographic factors had a small impact on vaccine willingness. However, early experience with vaccination had a significant impact. Thus, more than 70% who had influenza or COVID-19 vaccine were willing to receive the MPX vaccine. Some of the most significant concerns influencing vaccine acceptability were the safety and efficacy of the vaccine. Hence, it is strongly recommended to focus on disseminating information regarding the safety and efficacy of the MPX vaccine.

Despite the availability of effective vaccines that lower mortality and morbidity associated with COVID-19, many countries including Italy adopted strict vaccination policies and mandates to increase the uptake of the COVID-19 vaccine. Such mandates have sparked debates on the freedom to choose whether or not to get vaccinated. In this study, we examined the people’s belief in vaccine choice as a predictor of willingness to get vaccinated among a sample of unvaccinated individuals in Italy. An online cross-sectional survey was conducted in Italy in May 2021. The survey collected data on respondents’ demographics and region of residence, socioeconomic factors, belief in the freedom to choose to be vaccinated or not, risk perception of contracting and transmitting the disease, previous vaccine refusal, opinion on adequacy of government measures to address the pandemic, experience in requesting and being denied government aid during the pandemic, and intent to accept COVID-19 vaccination. The analysis employed binary logistic regression models using a hierarchical model building approach to assess the association between intent to accept vaccination and belief in the freedom to choose to vaccinate, while adjusting for other variables of interest. 984 unvaccinated individuals were included in the study. Respondents who agreed that people should be free to decide whether or not to vaccinate with no restrictions on their personal life had 85% lower odds of vaccine acceptance (OR=0.15 ;95% CI,0.09,0.23) after adjusting for demographic and socioeconomic factors and their risk perception of contracting and transmitting COVID-19. Belief in the freedom to choose whether or not to accept vaccinations was a major predictor of COVID-19 vaccine acceptance among a sample of unvaccinated individuals in Italy in May 2021. This understanding of how individuals prioritize personal freedoms and the perceived benefits and risks of vaccines, when making health care decisions can inform the development of public health outreach, educational programs and messaging.

There are scarce data regarding flu vaccination among people with HIV infection (PWHIV). The goal of this explorative study is to assess hesitancy toward influenza vaccination in a group of PWHIV during the pandemic. A questionnaire was administered to 219 patients vaccinated at our clinic during the 2020-2021 campaign. It evaluated subjects’ adherence over the last 3 seasonal vaccination campaigns, vaccine confidence, complacency and convenience, and the effect of the pandemic on the choice to vaccinate. The population was divided into two groups: fully adherent (all 3 campaigns, 117 patients) and non-fully adherent (1 or 2 campaigns, 102 patients). Adherence increased in non-fully adherent group in 2020-2021, but the pandemic did not affect the choice. Misbelieves emerged: influenza vaccine was considered protective SARS-CoV-2 (22.8% of total population); almost half of all patients thought influenza vaccine could improve their CD4+ cell level (57.3% in fully adherent, 40.2% in non-fully adherent, p<0.05). A quarter of the non-fully adherent group would not have vaccinated in a location other than our clinic (24.5% vs 11.9% in fully adherent group, p<0.05). Conclusively, offering a secure and private space for vaccination seems to encourage vaccination; healthcare professionals should improve counselling to increase adherence and correct misbeliefs.

Circular RNA (circRNA) vaccines are emerging as a revolutionary strategy in cancer immunotherapy, offering novel mechanisms for inducing robust and durable immune responses. Unlike traditional linear mRNA vaccines, circRNAs exhibit exceptional stability, enhanced translational efficiency, and resistance to exonuclease degradation, making them ideal candidates for vaccine development. This review delves into the fundamental principles underlying circRNA biology, highlighting their unique structural advantages and translational potential. We examine recent advancements in circRNA vaccine design, focusing on their application in oncology. As the circRNA-based cancer vaccine is a relatively novel approach, accounts of all the major studies describing the efficacy have been discussed. To maximize the anti-cancer effects of circRNA vaccines, we also investigate their combination with other immunotherapeutic modalities such as immune checkpoint inhibitors and adoptive cell therapies. Large-scale manufacturing, immunogenicity optimization, delivery systems, and other challenges and future directions in the sector are also discussed. This study aims to thoroughly analyse the state-of-the-art and potential future applications of circRNA vaccines in cancer immunotherapy, highlighting them as exciting possibilities for next-generation cancer therapies.

The potential adverse effects of coronavirus disease 2019 (COVID-19) vaccinations raise public concerns. Data from Taiwan’s Vaccine Injury Compensation Program (VICP) can provide valuable insights. This study analyzed preliminary application data for COVID-19 vaccine compensation in Taiwan’s VICP, focusing on applicants receiving vaccines between March 2021 and June 2022. Among the 2941 adverse events, 113 cases (3.8%) were deemed causally associated with vaccination, 313 (10.6%) were indeterminate, and 2515 (85.5%) had no causal association. Nearly half (47.6%) of applicants were over 60 years old, and 76.6% had a history of preexisting chronic dis-eases. Among the 426 vaccine-associated or indeterminate cases, the most common causes were hematological diseases and thrombosis. There were 920 mortality cases reported, and 97.4% were unassociated with vaccination. Only five deaths were judged to be associated with the COVID-19 vaccination, all involving the adenovirus vector vaccine and thrombosis with thrombocytopenia syndrome. In conclusion, most compensation applications were not causally linked to vaccination. Compared to other countries, the number of applications in Taiwan’s VICP is relatively high. These findings may indicate a need to adjust the application requirements for compensation in Taiwan’s program.

The COVID-19 pandemic continues to ravage the world, with the United States being highly affected. A vaccine provides the best hope for a permanent solution to controlling the pandemic. However, to be effective, a vaccine must be accepted and used by a large majority of the population. Structural equation modelling was used to analyze the relationships of several factors with attitudes toward potential COVID-19 vaccination. The survey was administered to 316 respondents across the United States by a survey corporation. Prior vaccine usage and attitudes predicted attitudes towards COVID-19 vaccination. Assessment of the severity of COVID-19 for the United States was also predictive. Approximately 68% of all respondents were supportive of being vaccinated for COVID-19, but side effects, efficacy, and length of testing remained concerns. Longer testing, increased efficacy and development in the United States were significantly associated with increased vaccine acceptance. Messages promoting COVID-19 vaccination should seek to alleviate the concerns of those who are already vaccine-hesitant. Messaging directed at the benefits of vaccination for the United States as a country would address the second predictive factor. Enough time should be taken to allay concerns about both short and long-term side effects before a vaccine is released.

COVID-19 pandemic disproportionately affected seven South Asian countries because of rampaging virus and weak health system response. Vaccination commenced in all countries during early 2021, once the vaccines became available in the international market. Vaccines were donated by international development partners, friendly countries and procured utilizing domestic resources and financial support from various agencies. All countries opted for a phasing of the vaccination by prioritizing high risk populations which included health care personnel, front line workers and elderly with comorbidities. Seven vaccines that had WHO emergency authorization usage were utilized in South Asia. India produced more than 2.4 billion doses of AstraZeneca vaccine and has indigenously developed five COVID-19 vaccines. Vaccine inequity was obvious and characterized by fewer people in South Asia vaccinated with single dose vis a vis the developed countries. Vaccine hesitancy was another obstacle that kept the vaccination rates low. Difficult to reach areas in Afghanistan, Bhutan, Maldives, Nepal could not fully access vaccines. South Asian countries need to strengthen their health system for efficient deployment of vaccines in future health emergencies. At the same time the global agencies and developed countries must address the issue of vaccine access to low-income countries to mitigate the impact of pandemic all over the world.

With COVID-19 vaccines slowly being rolled out in many countries, it is important to understand the public’s acceptance of being vaccinated. This study aims to study the willingness and motivations among residents of the cities of Caloocan, Malabon, and Navotas, Philippines to be vaccinated against COVID-19. Based on an online survey of 137 respondents, who willingly participated in the study, 71% will take a COVID-19 vaccine if it becomes available, with similar rates among respondents from Caloocan (82%), Malabon (83 %), and Navotas (81%). If a vaccine is proven safe and effective, more respondents (82%) will take a COVID-19 vaccine. Furthermore, safety against COVID-19 as well as the safety and effectiveness of vaccines are the primary factors why respondents are willing or unwilling to get a vaccine. The results highlight the need for effective messaging that promotes COVID-19 vaccination, with emphasis on the safety and effectiveness of the vaccine, and its benefits to the public, especially that the vaccines that will be delivered in the country in the next few months are not the most preferred brands by the respondents.

The recently approved maternal vaccination against respiratory syncytial virus (RSV) can reduce its burden among infants. Vaccine hesitancy/resistance can undermine the beneficial impact of RSV vaccination. The aim of this study was to assess the willingness of pregnant women in Jordan to receive RSV vaccination and its associated determinants. Face-to-face interviews were conducted in obstetrics/gynecology clinics in Jordan during January-February 2024, with convenience sampling. Attitude to RSV vaccination was assessed using the previously validated ABCDEF scale. A total of 404 pregnant women participated in the study with a mean age of 30 years. A majority of the participants showed willingness to receive RSV vaccination (n=313, 77.5%), with hesitancy among 25 participants (6.2%), and resistance among 66 participants (16.3%). Variables that were significantly associated with a higher RSV vaccine acceptance in multivariate analysis were: age <30 years (aOR: 2.45, p=0.010), undergraduates (aOR: 3.27, p=0.026), being a healthcare worker (aOR: 4.50, p=0.036), and the history of previous COVID-19/influenza vaccine uptake (aOR: 2.47, p=0.045). Two out of the six ABCDEF constructs were significantly associated with RSV vaccine acceptance, namely the “Advice” construct (aOR: 10.38, p<0.001) and the “Fear” construct (aOR: 21.49, p<0.001). This study highlighted the multifaceted nature of attitude towards maternal RSV vaccination among pregnant women. The study showed the role of demographic variables, prior vaccination experience, trust in credible health institutions and vaccine safety, and fear of RSV disease consequences in infants in shaping maternal attitude to RSV vaccination. Addressing these factors can help to effectively promote RSV vaccine uptake, subsequently helping to protect infants from the significant RSV disease burden.

Despite the importance of influenza vaccination for healthcare workers (HCWs), their uptake remains challenging. This study aimed to measure influenza vaccine hesitancy among HCWs in Nakhon Phanom province, Thailand. A representative cross-sectional survey was conducted at six hospitals during August – September 2020 using a self-administered questionnaire. HCWs delaying getting influenza vaccines, accepting but unsure, or refusing with doubts were categorized as hesitant. Those accepting without any doubts were classified as non-hesitant. Vaccine hesitancy determinants were identified by multivariable logistic regression analysis. A total of 338 participants (97%) completed the questionnaires; most were female nurses working at district hospitals without pre-existing chronic medical conditions. Nearly 60% of participants (197/338) exhibited influenza vaccine hesitancy, and significant factors included age above 50 years adjusted odds ratio [aOR] 3.2, 95% CI 1.3-8.5), fair knowledge of influenza/vaccination (aOR 0.4, 95% CI 0.2-0.8), and negative influence of other HCW (High level– aOR 2.3, 95% CI 1.1-4.8; Moderate level- aOR 2.1, 95% CI 1.1-4.4). Imparting updated information to the HCW combined with positive guidance from influential peers may help reduce this hesitancy.

Cameroon introduced the malaria vaccine in its routine immunization programme on 22 January 2024, in the 42 districts out of 200, among the most at risk of malaria. A cross-sectional analysis of data on vaccine key events in the introduction roadmap and vaccine uptake during the first 30 days was conducted. In addition to available gray literature related to the introduction of the malaria vaccine, data on malaria vaccine uptake by vaccination session, collected through a digital platform, were analyzed. A total of 1,893 reports were received from 22 January 2024 to 21 February 2024 from 766 health facilities (85% of overall completeness). Two regions out of 10 recorded less than 80% of completeness. As of 21 February 2024, 13,811 children have received the first dose of the malaria vaccine, including 7,124 girls (51.6%) and 6,687 boys (48.4%). Thirty six percent of children were vaccinated through outreach sessions versus 61.5% through sessions in fixed posts. The overall monthly immunization coverage with the first dose was 37%. Early results have shown positive attitudes towards and acceptance of malaria vaccines. Suboptimal completeness of data reporting and low coverage highlight persistent gaps and challenges in vaccine rollout.

Measles is targeted for elimination since 2001, with significant reduction in cases recorded worldwide, but outbreaks occur periodically due to immunization gaps. The present study analyzes the evolution of vaccination coverage rates (VCR) in Romania, a EU country with large measles epidemics during the last two decades, including an ongoing outbreak in 2023. Vaccination against measles is included in the National Immunization Program from 1979, initially as a single dose, and since 1994, with 2 doses. The vaccine uptake was initially high, with national VCR of &gt;97%. However, from 2010 onwards, the VCR dropped and remained constantly under 90%. This decline was caused by several factors, including a decreasing number of general practitioners, discontinuities in vaccine supply, emigration, with increased numbers of children lost to follow-up and a surge in vaccine hesitancy. Additional decreases in the already low levels of VCR were recorded during the COVID-19 pandemic: in 2022 the VCR reached the lowest level in the last decade, with 83.4% for the first dose (6.6% decrease compared to 2019) and 71.4% for the second dose (4.4% decrease compared to 2019), with important subregional differences. The constant suboptimal vaccination coverage rate in Romania threatens the progress toward measles elimination.

The effect of SARS-CoV-2 pandemic has been subsided significantly following the rapid development of vaccine. However, patients with cancer and immunosuppressed state, who are more prone to mortality and morbidity due to this infection, were excluded from majority of the vaccine trials. Moreover, suggested dose modification for cancer and immunosuppressed patients are often not followed because of lack of awareness or unavailability of vaccination schedule. This review will try to bridge this knowledge gap by summarizing the current suggestions of dose modification of COVID-19 vaccine for patients with cancer and immunosuppression.

This prospective study provides data on long-term humoral immunogenicity of a heterologous off-label vaccine regimen combining the adenoviral vectored ChAdOx1 nCoV-19 from Astra-Zeneca (ChAd) with the mRNA-1273 vaccine from Moderna (m1273) in comparison to two different homologous mRNA vaccine schedules. Of the 316 COVID-19 naïve adult health care workers (HCW) included to complete a survey on vaccine-associated symptoms (VAS), 197 had received the homologous BNT162b2 mRNA vaccine from Pfizer/BioNTech (BNT/BNT), 76 the homologous m1273/m1273, and 43 the heterologous ChAd/m1273 vaccine regimen. Concentration of antibodies against SARS-CoV-2 spike protein in plasma 5-7 months after the second vaccine dose was higher in the m1273/m1273 and ChAd/m1273 than the BNT/BNT vaccine group. The frequency of systemic VAS after first vaccine dose was 86% after ChAd compared to 35% and 39% after BNT and m1273, respectively (p &lt; 0.0001), and after second vaccine dose highest (89%) in the m1273/m1273 group (p &lt; 0.001). Individuals with systemic VAS achieved higher levels of antibodies irrespective of vaccine regimen. In conclusion, VAS serve as a strong predictor of long-term humoral immune response, and the heterologous ChAd/m1273 vaccine regimen provides an at least equal long-term humoral immune response compared with the standard vaccine regimens used in Denmark.

Background: This study aimed to evaluate whether measles vaccine uptake can be predicted directly or indirectly by parental perceptions about the availability of measles vaccine services with parental hesitancy towards the measles vaccine as a potential mediator. Methods: This was a community-based cross-sectional study conducted at Omdurman locality in Khartoum state, Sudan in February 2019. The study population included parents/ guardians having at least one child aged 2 -3 years old. Mediation analysis was conducted using two models, the ordinary least squares path analysis and multiple logistic regression. Results: a total of 495 responded and the mean age of the mothers who participated in the study was 31.1 (SD=5.73). A half of the respondents (50.1%) completed university education and nearly three-quarters of the respondents (74.7%) were housewives. After controlling for the other factors, including the mother’s age and the number of children, parental perception about the accessibility and availability of the measles vaccine influences the uptake of the measles vaccine indirectly through the mediation effect of measles vaccine hesitancy. Conclusions: We suggest that intervening in measles vaccine hesitancy in addition to measles vaccination access issues will have positive impact on the uptake and coverage of the measles vaccine in Sudan.

With the onset of the COVID19 pandemic, information technology has played a critical role in healthcare. A broad spectrum of information technology tools and applications played an essential role to create awareness of the COVID19 vaccination drive and its health benefits. We use the COVID-19 Global Beliefs, Behaviors, and Norms Survey for analysis of prevalence and factors associated with vaccination drives among men and women aged 20-80 years in 60 countries worldwide. Our analysis of the global survey offers a unique perspective about the role of information technology associated with vaccination drives involving social norms and human behavior among 437,236 respondents. The international survey was organized using a pre-registered randomized experiment demonstrating the role of technology in reaching out to people based in diverse communities and evaluating their beliefs, behavior, and social norms. The study shows that vaccine acceptance can vary due to descriptive norms. Our analysis shows 65.06% of people all over the globe are willing to get vaccinated and a large proportion of the population thinks that the COVID19 pandemic is a viable threat to the community and preventive measures need to be taken including vaccination drives.

Despite the research conducted worldwide, there is no treatment specific for SARS-CoV-2 infection with efficacy proven by randomized controlled trials. A chance for a breakthrough is vaccinating the majority of the global population. The public opinion surveys on vaccine hesitancy prompted our team to investigate the Polish medical community's attitude towards the SARS-CoV-2 and influenza vaccinations. In-person and online surveys of Healthcare Workers (HCWs): doctors, nurses, medical students, and other allied health professionals (n=419) took place between 14.09.2020 and 5.11.2020. In our study, 68.7% of respondents would like to be vaccinated with the COVID-19 vaccine. The safety and efficacy of vaccination against COVID-19 would persuade 86.3% of hesitant and those who would refuse to be vaccinated. 3.1% of all respondents claimed that no argument would convince them to get vaccinated. 61.6% of respondents declared a willingness to receive an influenza vaccination, of which 83.3% were also inclined to receive the planned COVID-19 vaccination. Although a significant part of respondents - 62.5% (262/419) indicated, they trusted the influenza vaccine more than the COVID-19 vaccine in direct comparison, more respondents intended to get the COVID-19 vaccination than the influenza vaccine in the 2020/2021 season.

Despite the crucial role the COVID-19 vaccine played in curbing the pandemic, a significant portion of Black and African American individuals expressed hesitancy in being vaccinated. This review aimed to identify the determinants of COVID-19 vaccine hesitancy among Black and African American individuals in the USA. The literature search was conducted in December 2022 according to the PRISMA criteria focusing on empirical studies. Data extraction methods, critical appraisal, and secondary thematic analysis were conducted on both quantitative and qualitative studies. Sixteen quantitative studies identified key factors associated with vaccine hesitancy such as confidence in vaccine effectiveness, safety, and trust in the healthcare system. 14 qualitative studies revealed major themes of mistrust, fear, and information needs, including historical mistrust, concerns about the vaccine development process, and contemporary institutional mistrust. The synthesis of quantitative and qualitative findings derived from this review provides a nuanced understanding of determinants of vaccine hesitancy in Black and African American communities in the USA, offering a foundation for the development of evidence-based interventions. Mistrust in the healthcare system, fear, and informational gaps on vaccine safety and effectiveness have been identified as significant barriers to vaccination, demanding targeted interventions.

The global COVID-19 pandemic has affected all spheres of human life, resulting in millions of deaths and overwhelming medical facilities. Moreover, the world has witnessed great financial hardship because of job losses resulting in economic havoc. Many sections of society have contributed in different ways to slow the spread of the virus and protect public health. For example, medical scientists are praised for their efforts to develop COVID-19 vaccines. Clinical trials have shown that the COVID-19 vaccines are highly effective in preventing symptomatic COVID-19 infections. However, many people around the world have been hesitant to get vaccinated. Vaccine misconceptions have emerged and increased due to a combination of factors, including the availability of information on the Internet and the influence of celebrities and opinion leaders. In this context, we have analyzed ChatGPT responses to relevant queries on vaccine misconceptions. The positive responses and supportive opinions provided by the AI chatbot could be instrumental in shaping people’s perceptions of vaccines and in encouraging users to get vaccinated and reduce misconceptions.

Older adults (age ≥65) are at high risk of influenza morbidity and mortality. This study evaluated the impact of a hypothetical two-dose influenza vaccine regimen per season to reduce symptomatic flu cases by providing preseason (first dose) and mid-season (second dose) protection to offset waning vaccine effectiveness (VE). The Framework for Reconstructing Epidemiological Dynamics (FRED), an agent-based modeling platform, was used to compare typical one-dose vaccination to a two-dose vaccination strategy. Primary models incorporated waning VE of 10% per month and varied influenza season timing (December through March) to estimate cases and hospitalizations in older adults. Additional scenarios modeled reductions in uptake and VE of the second dose, and overall waning. In seasons with later peaks, two vaccine doses had the largest potential to reduce cases (14.4% with February peak, 18.7% with March peak) and hospitalizations (13.1% with February peak, 16.8% with March peak). Reductions in cases and hospitalizations still resulted but decreased when 30% of individuals failed to receive a second dose, second dose VE was reduced, or overall waning was reduced to 7% per month. Agent-based modeling indicates that two influenza vaccine doses could decrease cases and hospitalizations in older individuals. The highest impact occurred in the more frequently observed late-peak seasons. The beneficial impact of the two-dose regimen persisted despite model scenarios of reduced uptake of the second dose, decreased VE of the second dose, or overall VE waning.

Influenza viruses pose a continuing public health challenge due to their high mutation rate and the need for annual vaccine updates. A recent advancement in nanoparticle-based vaccine technology for developing a universal influenza vaccine. We focused on four key studies investigating the use of lipid nanoparticles (LNPs), nanoparticle immunogens, and multivalent epitope-based nanoparticles. The studies demonstrated promising results. The single-dose mRNA -LNP vaccine targeting five influenza B virus antigens effectively protected mice from a broad range of strain. Additionally, nanoparticle immunogens designed to display multiple influenza virus strains induced broad protective immunity in mice. Furthermore, LNPs enhanced the efficacy of mRNA and protein subunit vaccines by stimulating robust T follicular helper cell and humoral responses. Finally, an intranasal multivalent epitope-based nanoparticle vaccine offered broad protection against diverse influenza viruses. These findings highlight the potential of nanoparticle-based approaches for developing a universal influenza vaccine that offers long-lasting and broad-spectrum protection. Further research is needed to evaluate the safety and efficacy of these novel vaccines in humans.

Infectious diseases are one of the leading causes of death among children under the age of 5 with 60% of those deaths preventable with prophylaxis. Vaccinations prove to be the most succesfull and effective public health tool of infectious dieases preventions. Poland first implemented a program of mandatory childhood vaccinations in 1960. The program is updated each year and provides parents with a clear schedule to follow. The program includes vaccinations against 12 diseases (tuberculosis, hepatitis B, rotaviral disease, diphtheria, pertussis, tetanus, Haemophilus influenzae, Streptococcus pneumoniae, poliomyelitis, measles, mumps and rubella) mandatory for all children and funded by the government. It also includes recommended vaccinations which costs are covered by a patient. Immunization rates are monitored nationwide and reported to the Chief Sanitary Inspector. With recent outbreaks of infectious diseases among young children the obligation lies on the government to provide childhood immunizations, and largely on the physicians to provide reliable education about infectious diseases in children and safety of vaccinations to the parents.

Utility of vaccine campaigns to control coronavirus disease 2019 (COVID-19) is not merely dependent on vaccine efficacy and safety. Vaccine acceptance among the general public and the healthcare workers, appears to have a decisive role for successful control of the pandemic. The aim of this review was to provide an up-to-date assessment of COVID-19 vaccination acceptance rates worldwide. A systematic search of the peer-reviewed English survey literature indexed in PubMed was done on December 25, 2020. Results from 30 studies, met the inclusion criteria and formed the basis for final COVID-19 vaccine acceptance estimates. Results of an additional recent survey from Jordan and Kuwait was considered in this review as well. Survey studies on COVID-19 vaccine acceptance rates were found from 33 different countries. Among adults representing the general public, the highest COVID-19 vaccine acceptance rates were found in Ecuador (97.0%), Malaysia (94.3%), Indonesia (93.3%) and China (91.3%). On the other hand, the lowest COVID-19 vaccine acceptance rates were found in Kuwait (23.6%), Jordan (28.4%), Italy (53.7), Russia (54.9%), Poland (56.3%), US (56.9%), and France (58.9%). Only eight surveys among healthcare workers (doctors, nurses) were found, with vaccine acceptance rates ranging from 27.7% in the Democratic Republic of the Congo to 78.1% in Israel. In a majority of survey studies among the general public (62%), the acceptance of COVID-19 vaccination showed a level of ≥ 70%. Low rates of COVID-19 vaccine acceptance were reported in the Middle East, Russia, Africa and several European countries. This could represent a major problem in the global efforts that aim to control the current COVID-19 pandemic. More studies are recommended to address the scope of COVID-19 vaccine hesitancy. Such studies are particularly needed in the Middle East Africa, Eastern Europe, Central Asia, Middle and Latin America.

Outbreaks of avian pathogens such as Newcastle disease virus, avian influenza virus and Salmonella have a major impact on economies and food security worldwide. Some pathogens also pose a significant zoonotic potential, especially avian influenza viruses. Vaccination plays a key role in controlling many poultry diseases and there are many vaccines licenced in the United Kingdom for diseases of poultry caused by viruses, bacteria, and parasites. However, these vaccines often do not provide complete protection and can cause unwanted side effects. Several factors affect the potency of poultry vaccines including the type of vaccination used, the mechanism of delivery and the use of adjuvants. Advancements in technology have led to the study and development of novel vaccines and vaccine adjuvants for use in poultry. These induce stronger immune responses compared to current vaccine technology and have the potential to protect against multiple poultry diseases. This review aims to discuss existing poultry vaccine technology, the effect of delivery mechanisms of vaccine efficacy, the use of current and novel adjuvants, the ability to target antigen to antigen presenting cells, the use of probiotics, multivalent vaccines, and nanotechnology to enhance the potency of poultry vaccines.

Vaccine refusal and hesitancy pose a critical challenge to public health, leading to delays in vaccination and compromising herd immunity. To address this issue, we conducted a comprehensive observational study on the adult Spanish population in 2021. Through an online questionnaire, we explored the sociodemographic and sociocultural factors, beliefs, and opinions of those refusing or holding hesitancy about vaccines, and their vaccination behaviours by vaccine type and sex. Our findings revealed that vaccine refusal rates were relatively low (16.8%), and mainly associated with influenza vaccination (10.3%). Greater refusal of vaccination was observed in over 60 years old, in those expressing hesitancy due to vaccine components and opposing free and compulsory vaccination, unaware that vaccination protects the community and being against consuming cow’s milk and the use of infant formulas for breastfeeding. Vaccine hesitancy was greatest in individuals under 31 years old, women, parents of children under 15 years old, against compulsory vaccination, unaware that vaccination protects the community, with hesitancy due to vaccine costs, and in favour of alternative and complementary treatments. These insights underscore the need for strategies to improve education about vaccination and dispel misconceptions are crucial for effectively reducing vaccine refusal and hesitancy across the population.

Tetanus toxoid (TT) vaccination during pregnancy has been proven as an effective preven-tive measure to reduce the incidence of maternal and neonatal morbidity and mortality worldwide. This study aimed to assess the determinants of TT vaccine uptake among pregnant women in two public maternity specialized hospitals in Sudan. A hospi-tal-based cross-sectional study was conducted in two public hospitals, Omdurman Ma-ternity and AL-Saudi hospitals in Omdurman, Khartoum State in Sudan, from February to April 2020. Logistic regression analysis was carried out to identify factors associated with receiving three or more doses of TT vaccine among pregnant women (protected against tetanus), presented as Odds ratios, with p-values <0.05 considered significant (at 95% confidence interval). The study recruited 350 pregnant women, with 313 participants in-cluded in the analysis. This study found that only 40% of the pregnant women received 3 doses or more (protected) of TT vaccine during their current pregnancy. Pregnant women who attended Al Saudi hospital were less likely to be protected against Tetanus (received ≥ 3 doses) compared to those who attended Omdurman hospital [OR= 0.49 (95%C.I 0.29-0.82), p-value <0.05]. Furthermore, the number of children at home was a significant predictor of mothers’ immunization status as those with five children or more were ten times more to be protected against tetanus [OR= 10.54 (95% C.I 4.30-25.86), p-value <0.05]. We conclude that this low rate of TT vaccine uptake found in this study among pregnant women increases the number of newborn babies susceptible to contracting neonatal tetanus. This study provides useful information that can inform the will increase in the probabilities of morbidities and mortalities that result from maternal and neonatal tetanus. The findings of this study should be considered in development of communication strategies targeting and prioritizing at-risk groups to increase TT vaccine uptake among pregnant women in Sudan.

We study here what can be learned from our experience with COVID-19 vaccination for an initially naïve population, that can inform planning for vaccination against the next novel, highly transmissible pathogen. We focus on the first two pandemic years (wild strain through Delta), because after the Omicron wave in early 2022, few people were still SARS-CoV-2-naïve. Almost all were vaccinated, infected, or often both. We review the evidence on COVID-19 vaccine effectiveness (VE), waning effectiveness over time, and what we should expect about VE and waning from a future pathogen. As a basis for our analysis, we conducted a PRISMA-compliant review of all studies on PubMed through August 15, 2022 reporting VE against four endpoints: any infection, symptomatic infection, hospitalization, and death, for the four principal vaccines used in developed Western countries (BNT162b2, mRNA1273, Ad26.CoV2.S, and ChAdOx1-S). The mRNA vaccines (BNT162b2, mRNA1273) had high initial VE against all endpoints but protection waned after approximately six months, with BNT162b2 declining faster than mRNA1273. Both mRNA vaccines initially outperformed the viral vector vaccines. A third “booster” dose, roughly six months after the primary doses, substantially reduced symptomatic infection, severe disease, and mortality, and in hindsight should be seen as part of the normal vaccination schedule.

Avian mutations in vaccine strains obtained from embryonated eggs could impair vaccine effec-tiveness. We performed a systematic review and meta-analysis of the adjusted relative vaccine effectiveness (arVE) of seed cell-cultured influenza vaccines (ccIV) compared to egg-based influ-enza vaccines (eIV) in preventing laboratory-confirmed influenza related outcomes (IRO) or IRO by clinical codes, in subjects 18 and over. We completed the literature search in January 2021; ap-plied exclusion criteria, evaluated risk of bias of the evidence, and performed heterogeneity, pub-lication bias, qualitative, quantitative and sensitivity analyses. All estimates were computed us-ing a random approach. International Prospective Register of Systematic Reviews, CRD42021228290. We identified 12 publications that reported 26 adjusted arVE results. Five publications reported 13 laboratory confirmed arVE and seven reported 13 code-ascertained arVE. Nine publications with 22 results were at low risk of bias. Heterogeneity was explained by season and risk of bias. We found a significant 11% (8 to 14%) adjusted arVE favoring ccIV in preventing any IRO in the 2017-2018 influenza season. The arVE was 3% (-01 to 7%) in the 2018-2019 influenza season. We found moderate evidence of a significant advantage of the ccIV in preventing IRO, compared to eIV, in a well-matched A(H3N2) predominant season.

This is a case study of a 55-year-old patient who died four months after receiving the mRNA-vaccine BNT162b2 (Pfizer-BioNTech) against COVID-19 as a second dose, following an initial vaccination with the ChAdOx1 nCov-19 vector vaccine (AstraZeneca) two months earlier. The autopsy diagnosis revealed general atherosclerosis. The histopathologic analyses of cardiac tissue demonstrated the presence of a thrombus occluding the right coronary artery (RCA) without evidence of plaque rupture. As a substitute trigger of clotting, the RCA presented with characteristics of acute lymphocytic vasculitis that extended to vasa vasorum in the adventitia and vessels in adjacent adipose tissue. Microthrombi were occasionally detected in these small vessels. It was obvious that lymphocytic myocarditis had been a chronic ongoing process temporally distinct from acute myocardial infarction. The myocardium contained patchworks of fibrotic areas alongside foci of displaying acute inflammation and fresh myocyte damage. SARS-CoV-2 Spike protein, but not nucleocapsid protein was sporadically detected in vessel walls by immunohistochemical assay. The cause of death was determined to be acute myocardial infarction and lymphocytic myocarditis. These findings indicate that myocarditis, as well as thrombo-embolic events following injection of spike-inducing gene-based vaccines, are causally associated with a injurious immunological response to the encoded agent. Because of the fact that the immune response to a first gene-based vaccination is very low in comparison with the immune response to the second vaccination, the found adverse events has rather to be attributed to the mRNA-based second vaccination as to the initial vector-based one.

The current report represents a case of a 77-year-old man with Parkinson’s disease who died three weeks after receiving his third COVID-19 vaccination in January 2022. The patient was first vaccinated in May 2021 with the ChAdOx1 nCov- 19 vector vaccine, followed by two more doses with the BNT162b2 mRNA vaccine in July and December 2021. The family of the deceased requested an autopsy due to the ambivalent clinical features noted before death. The underlying illness (Parkinson’s disease) was confirmed by autopsy. However, no sign of a florid COVID-19 was discovered. Meanwhile, the immunohistochemical staining of the brain and heart revealed previously undiagnosed conditions. The brain, in distinctive, revealed multifocal necrotizing encephalitis with massive inflammatory lymphocyte infiltrates. In addition, the heart showed signs of serious myocarditis. Finally, immunohistochemical staining revealed that the SARS-CoV-2 spike protein was evident in the tissues investigated. Based on these immunohistochemical findings, it appears that the inflammatory changes in the patient's brain tissues are most likely the result of immunological processes. Concurrently, the absence of SARS-CoV-2 nucleocapsid-protein was evidenced, indicating that the detected spike-protein is unrelated to a SARS-CoV-2 infection. If such an infection was the cause of the spike protein, the SARS-CoV-2 nucleocapsid protein would also be detectable. As a consequence, the confirmed presence of the spike protein had to be attributed to the previous vaccination with the BNT162b2 mRNA vaccine that the deceased patient had received.

(1) Background: The monkeypox virus (MPV) is a double-stranded DNA virus belonging to the Poxviridae family, Chordopoxvirinae subfamily, and Or-thopoxvirus genu. It was called monkeypox because it was first discovered in monkeys, in a Danish laboratory, in 1958. However, the actual reservoir for MPV is still unknown. (2) Methods & Results: We have reviewed the existing literature on the options for Monkeypox virus. There are three available vaccines for orthopoxviruses: ACAM2000, JYNNEOS, and LC16, with the first being a replicating vaccine and the latter being non or minimally replicating. (3) Conclusions: Smallpox vaccinations previously provided coincidental im-munity to MPV. ACAM2000(a live‐attenuated replicating vaccine) and JYNNEOS (a live‐attenuated, non-replicating vaccine) are two US FDA‐approved vaccines that can prevent monkeypox. However, ACAM2000 may cause serious side effects, including cardiac problems, whereas JYNNEOS is associated with fewer com-plications. The recent outbreaks across the globe have once again highlighted the need for constant monitoring and the development of novel prophylactic and therapeutic modalities. Based on available data, there is still a need to develop an effective and safe new generation of vaccines specific for monkeypox that are killed or mRNA before monkeypox is declared a pandemic.

The SARS-CoV-2 virus (COVID-19) has led to an initiative to develop safe and effective vaccines for public health safety. In December 2020, the United States Food and Drug Administration (FDA) administered an Emergency Use Authorization (EUA) for the Pfizer-BioNTech COVID-19 vaccine. Other vaccines from Johnson & Johnson, Moderna, and AstraZeneca shortly followed. This paper aims to examine the EUA process for COVID-19 vaccine approvals, including the requirements for the safety and efficacy of data, along with the role of the FDA and EMA in the approval process. Further, public concerns about vaccine approvals, including issues on the approval process's safety, efficacy, and speed, were also discussed. Using qualitative analysis of the extracted studies, trends and insights into the factors influencing public acceptance of COVID-19 vaccines, such as vaccine hesitancy and misinformation, were discussed. Overall, a transparent and rigorous regulatory process for vaccine approval is critical for education efforts between policymakers, vaccine developers, and the public to address concerns for increased population vaccine uptake.

Bluetongue is not a contagious disease. It spreads very quickly and uncontrollably, considering that it is a vec-tor-borne disease transmitted by the genus Culicoides. Climate change has led to the fact that vectors and dis-eases have spread to the top of Northern Europe, causing great economic losses in livestock production. Even greater problem is controlling the disease, because numerous species of domestic and wild ruminants are sus-ceptible to bluetongue. The most effective tool against bluetongue disease is vaccination. There is no ideal vaccine against bluetongue virus (BTV) due to the serotype diversity of the strains. Thus, there is need for a vaccine for at least for 24 clinically significant serotypes. Sometimes it is difficult to obtain the desired amount of vaccine against a defined serotype on the market, and this led to the need for a new vaccine against blue-tongue disease. We tested an experimental inactivated novel vaccine against BTV4. Master seed BTV4 has been examined and characterized by sequencing. The novel BTV4 vaccine induce the onset of immunity at least at day 21 after the application of the first dose in more than 80% of vaccinated individuals, while specific antibodies against BTV are detected by the ELISA test for more than a year. Along with our laboratory results, the preliminary results of safety and efficacy trials are also presented. The side effects of novel vaccine are within the limits of permissible local reactions without generalized changes of health status, while the serology and challenge test leads to the conclusion that novel vaccine protects high percentage of vaccinated individuals against BTV4 or causes a significant reduction in the intensity and duration of the clinical signs in the vac-cinated sheep. Based on the trial results, new vaccine has given encouraging results in quality, safety and pre-liminary efficacy tests. Thus, we believe that a new vaccine against BTV is on the horizon. Keywords: bluetongue virus, inactivated vaccine, candidate, quality of vaccine, safety, efficacy We confirm that neither the manuscript nor any parts of its content are currently un-der consideration for publication with or published in another journal. All authors have approved the manuscript and agree with its submission to Vaccines.

A number of studies suggested that influenza vaccination can provide protection against COVID-19 but the underlying mechanisms that could explain this association is still unclear. In this study, the effect of the 2021/2022 seasonal influenza vaccination on the immune response to the booster dose of anti-SARS-CoV-2 vaccination was evaluated in a cohort of healthy individuals. One hundred and thirteen participants were enrolled, and 74 of them with no prior COVID-19 diagnosis or significant co-morbidities were considered for the analysis. Participants received the anti-influenza tetravalent vaccine and the booster dose of the anti-SARS-CoV-2 vaccine or the anti-SARS-CoV-2 vaccine alone. Blood was collected before and 4 weeks after each vaccination and 12 weeks after SARSCoV2 vaccination and analyzed for anti-flu and anti-spike-specific antibody titers and for in vitro influenza and SARS-CoV-2 neutralization capacity. Results indicated an increased reactivity in subjects who received both influenza and SARSCoV2 vaccinations, as compared to those who received only the SARS-CoV-2 vaccine, with sustained anti-spike antibody titers up to 12 weeks post-vaccination. Immune response to influenza vaccine was evaluated and individuals were stratified as high or low responders. High responders showed increased antibody titers against SARSCoV2 vaccine both after 4- and 12-weeks post-vaccination. On the contrary, the individuals classified as low responders were less responsive to the SARS-CoV-2 vaccine. These data indicate that both external stimuli, such as influenza vaccination, and the host's intrinsic ability to respond to stimuli play a role in the response to vaccine.

This research follows the publication of recent scoping and systematic reviews of existing literature on vaccine literacy (VL), its relationship to vaccine hesitancy (VH), and associated variables, such as vaccination beliefs, attitudes, and behaviors towards immunization. In this review, 17 articles were selected, published between December 2022 and November 2023, in which VL tools were used, most of which support the notion of a negative association between VL and VH, although not confirmed by others. Moreover, the definitions of the variables under consideration were not homogeneous between studies, some aimed to evaluate the association of VL with vaccine confidence, while others were more focused on outcomes such as willingness to be vaccinated or vaccine uptake. The complexity of the factors underlying VL, and the heterogeneity of the methods applied in the studies, in particular the limitations of cross-sectional surveys, still make it difficult to have a comprehensive understanding of the role of VL. Therefore, it is important to develop future assessment tools that consider not just the measurement of psychological factors connected to the motivational aspect of VL, but also those related to knowledge and competencies. For this purpose, a theoretical framework is proposed, where the positioning of VL at the intersection between antecedents and beliefs/attitudes leading to behaviors explains why and how VL serves as a tool and a critical, direct, or mediating driver of vaccination choices, overcoming VH and increasing vaccination rates, operating at personal, as well as at organizational and community level.

Lyme disease is the most common tick-borne illness in the United States, Europe, and Asia. Borrelia burgdorferi, a spirochete bacterium transmitted by the tick vector Ixodes scapularis, causes Lyme disease in the U.S. If untreated, Lyme arthritis, carditis, and meningitis will occur. Given the absence of a human Lyme disease vaccine, we developed a vaccine using the rabies virus vaccine vector, BNSP333, and an outer surface borrelial protein BBI39. To incorporate BBI39 into the RABV virion, we generated a chimeric BBI39 antigen, BBI39RVG, by fusing it with the final amino acids of the RABV glycoprotein. Here we demonstrated that BBI39RVG antigen was incorporated into the RABV virion, and mice vaccinated with our RABV-BBI39RVG vaccine induced high amounts of BBI39-specific antibodies which are maintained long-term. The BBI39 antibodies neutralized Borrelia in vaccinated mice when challenged with Borrelia burgdorferi by either syringe injection or infected ticks, and reduced Lyme disease pathology.

Our aim was to evaluate the immune response of healthcare workers included in the RIPOVAC study, after receiving a booster dose (third dose), in terms of intensity and persistence of induced antibodies. In the second phase of RIPOVAC study, between December 2021 and January 2022, eight months after the second dose, 389 voluntary, immunocompetent, non-pregnant healthcare workers received a booster dose of SARS-CoV-2 vaccine, and a serum sample was obtained. Two groups of patients were established: with and without previous SARS-CoV-2 infection. In order to quantify anti-S1 IgG (AU/mL) we used CMIA (Abbott). All the health workers were anti-S IgG positive 8 months after receiving the booster dose of the vaccine, with a mean of 17040 AU/mL. In 53 patients without previous infection, antibody levels had increased by a mean of 10762 AU/mL. This figure is 7 times higher than the one produced after the second dose (1506 AU/mL). The booster dose produces a robust elevation of the antibody level, which persists at 8 months with levels up to values significantly higher than those reached after the second dose, that allow to predict a persistence of more than one year. The study demonstrates the efficacy of the booster dose of anti-SARS-CoV-2 vaccines.

On 11th March 2020, the World Health Organization declared COVID-19 as a pandemic. Vaccination programs have advanced greatly in the global health period, despite widespread anti-vaccination attitudes and misinformation. Vaccine hesitancy of COVID-19 vaccine is currently a major issue in Saudi Arabia. This cross-sectional study was carried out from June 25, 2021 to October 2021 in order to investigate the knowledge levels of acceptance and hesitancy of COVID-19 vaccine among Saudi’s nationals. The data was collected through a close-ended structured questionnaire from a total of 565 respondents. Overall, 78.41% respondents were female, 62.48% having university level education and 61.06% were unemployed. Majority of the participants 82.30% (n=465) think that Pfizer vaccine has the highest efficiency against COVID-19. Our study concludes that majority of the participants have satisfactory knowledge about COVID-19 vaccination. Concerns over vaccine components, effectiveness of vaccine and possible side effects are among the key causes for vaccine hesitancy.

The urgent need for effective, safe and equitably accessible vaccines to tackle the ongoing spread of COVID-19 led researchers to generate vaccine candidates targeting varieties of immunogens of SARS-CoV-2. Because of its crucial role in mediating binding and entry to host cell and its proven safety profile, the subunit 1 (S1) of the spike protein represents an attractive immunogen for vaccine development. Here, we developed and assessed the immunogenicity of a DNA vaccine encoding the SARS-CoV-2 S1. Following in vitro confirmation and characterization, the humoral and cellular immune responses of our vaccine candidate (pVAX-S1) was evaluated in BALB/c mice using two different doses, 25 µg and 50 µg. Our data showed high levels of SARS-CoV-2 specific IgG and neutralizing antibodies in mice immunized with three doses of pVAX-S1. Analysis of the induced IgG subclasses showed a Th1-polarized immune response as demonstrated by the significant elevation of spike-specific IgG2a and IgG2b compared to IgG1. Furthermore, we found that immunization of mice with three doses of 50 µg of pVAX-S1 could elicit significant memory CD4+ and CD8+ T cell responses. Taken together, our data indicates that pVAX-S1 is immunogenic and safe in mice and is worthy of further preclinical and clinical evaluation.

Vaccination against Newcastle disease (ND), a devastating viral disease of chicken, is often hampered by thermal inactivation of the live vaccines, in particular in tropical and hot climate conditions. In the past “thermostable” vaccine strains (I-2) have been proposed to overcome this problem. In the current study, we compared the thermal stability of 6 commercially available ND vaccines. Subjected to 37°C as lyophilized preparation, two vaccines containing I-2 strains were more sensitive to inactivation than a third I-2 vaccine or when compared to three other vaccines based on different strains. However, after reconstitution strains proved to have a comparable tenacity. Interestingly, all vaccines retained a sufficient virus dose for protection (106 EID50) after 1 day at 37°C, still. However, experiments exposing ND-vaccines to elevated temperatures of 51°C and 61°C, clearly demonstrated inactivation of all dissolved vaccines within 2 to 4 hours. The data indicate preparation that specific factors may influence thermal stability rather than strain specific characteristics. Regardless of the ND strain used, the appropriate cold chain is mandatory for live ND-vaccines.

The COVID-19 pandemic has had a significant impact on every individual in the United States. The launch of the COVID-19 vaccines is estimated to have averted millions of deaths and reduced over 18 million COVID-19 related hospitalizations. In September 2023, the updated 2023-2024 COVID-19 vaccine that include a monovalent component that corresponding to the omicron variant XBB.1.5 reflecting the predominant circulating variant at the time of strain selection, was approved and was recommended for use in all people ≥ 6 months of age. Despite this recommendation, the US uptake of the updated COVID vaccines over the 2023-2024 season has been far from optimal, placing many people at unnecessary risk of severe COVID-19 outcomes. This paper provides an overview of the current state of COVID-19 in 2023-2024, and barriers to vaccine uptake. With the continued evolution of the virus, the potential for more virulent variants and the lower public acceptance of vaccination, the potential barriers that contributed to low vaccine uptake are explored, as well as to provide solutions for improving COVID-19 protection for future seasons.

Background In 2016, Global Polio Eradication Initiative (GPEI) recommended cessation of type 2 oral poliovirus vaccine (OPV) and OPV using countries switched from trivalent to bivalent OPV (bOPV) with addition of inactivated poliovirus vaccine (IPV) in the routine immunization schedule. The current GPEI strategy 2022-2026 includes bOPV cessation plan and switching to IPV standalone or the combination vaccine schedules in future. The focus of our study was to evaluate immunogenicity of monovalent OPV type 1 (mOPV1) with IPV and IPV only schedules. Methods This was a three-arm, multi-center randomized controlled trial conducted in 2016-2017 in India. Participants, at birth, were randomly assigned to bOPV-IPV (Arm A) or mOPV1-IPV (Arm B) or IPV (Arm C) schedules. Serum specimens collected at birth, 14-, 18- and 22- weeks age were analyzed with standard microneutralization assay for all three poliovirus serotypes. Results Results of 598 participants were analyzed. The type 1 cumulative seroconversion rates four weeks after completion of the schedule at 18 weeks were 99.5% (97.0-99.9), 100.0% (97.9-100.0) 96.0% (92.0-98.1) in Arms A (4bOPV+IPV), B (4mOPV1+IPV) and C (3IPV) respectively. Type 2 and type 3 seroconversion at 18 weeks were 80.0% (73.7-85.1), 76.9% (70.3-82.4), 93.2% (88.5-96.1) and 100.0% (98.0-100.0), 81.9% (75.6-86.8), 99.4% (96.9-99.9) respectively in the three arms. Conclusions This study shows high efficacy of different polio vaccines for serotype 1 in all three schedules. Type 1 seroconversion rate of mOPV1 is non-inferior to bOPV. All the vaccines provide high type specific immunogenicity. The program can adopt the use of different vaccines or schedules depending on epidemiology from time-to-time.

With its unique properties and potential applications, nanoparticle-based delivery platforms for vac-cines have gained significant attention in recent years. Nanoparticles have the advantages of enhancing immunogenicity, targeting delivery and improving stability, providing a new solution for drug and vaccine delivery. And in some clinical studies, a variety of nanoparticle delivery platforms have been gradually applied to a wide range of vaccine applications. Current research priorities are exploring various types of nanoparticles as vaccine delivery system to enhance vaccine stability and immunogen-icity. Lipid nanoparticles have shown promising potential in preclinical and clinical studies to efficiently deliver antigens to immune cells. Moreover, lipid nanoparticles (LNPs) and other nanoparticles as nu-cleic acids especially mRNA delivery system, have shown vast potential for vaccine development. In this review, we present various vaccine platforms with an emphasis on nanoparticles for mRNA nano-vaccine delivery vehicles. We introduce several novel nanoparticles delivery platforms for mRNA vac-cine such as lipid, polymer, protein-based nanoparticle and so on. In addition, we overview the an-ti-tumor immunity of nanovaccine against different tumors in cancer immunotherapy. Finally, we give an outlook future perspectives and remaining challenges for this promising technolo-gy-nanoparticle-based delivery platforms for vaccines.

Varicella (chickenpox) is one of the most common infectious diseases in preschool children and can be prevented by immunization. While immunization program promotes higher vaccine coverage, there are still challenges with implementing vaccination programs particularly in low-income countries. Economic barriers can increase inequality in vaccination, which highlights the importance of distributing cost-effective varicella vaccines. Varicella vaccines have been developed with two main Varicella-Zoster Virus (VZV) strains globally: MAV/06 and Oka strains. Most of the vaccines are based on the Oka strain, while MAV/06 strain vaccines were exclusively developed by GC Biopharma. Although more than 30 million doses of MAV/06 vaccines as cost-effective vaccines have been distributed internationally, there is no comprehensive review on safety, immunogenicity, and effectiveness of MAV/06 vaccines in the literature. This paper aims to summarize and present more than 30 years of accumulated evidence from research on safety, immunogenicity, and effectiveness of MAV/06 vaccines. We expect that MAV/06 vaccines as cost-effective varicella vaccines make a significant contribution to improving global public health and health equality in children.

This tutorial is organized into three major sections—viruses, vaccines and the race for a Covid-19 vaccine. The goal is to provide enough background on viruses, history of vaccines, and the science of vaccinology founded on the principles of immunity. The hope is that this will enable us to understand the challenges, methods and prospects for developing a safe and effective vaccine against SARS-CoV-2. Many important viruses such as smallpox, HIV, HCV and SARS-CoV-2 which is responsible for causing the Coronavirus disease 2019 (Covid-19) are presented in detail, which is then followed by a description of different vaccine development methods and strategies. The tutorial then discusses different candidate SARS-CoV-2 vaccines and provides specific details of many of the prospective vaccines on the leader-board which are undergoing clinical trials. The tutorial concludes with a realistic projection for a safe and effective vaccine against SARS-CoV-2 based on the historical scientific record.

We present a case of serious and progressive neuropathy shortly following administration of the herpes zoster subunit (HZ/su) vaccine. The progressive neuropathy occurred a week following the vaccination and progressed until discharge 16 days post admittance. Mild patient’s symptoms persist. The development of neuropathy following HZ/su is exceedingly rare, with an attributable risk of 3 cases per million vaccines administered. A black box warning was issued for this indication, although diagnosis and treatment were not confirmed for this patient. Reporting cases like this is crucial for a comprehensive understanding of vaccine risks and to characterize the underlying etiology of these serious adverse events.

Introduction: Adverse events related to vaccines are reactions that can lead to serious complications, in the present that we live at the publication of this article with the need to generate high rates of vaccination have been presented in the case of vaccine agents against COVID-19 adverse events, with thrombotic events being the most important. Case Presentation: This is a 37-year-old female patient who presents 11 days after ChAdOx1-S vaccination against COVID-19 presents with intense headache associated with symptoms of intracranial hypertension, she was initially taken to simple cranial tomography showing presence of cerebral edema and indirect signs of cerebral venous thrombosis, it is proposed to carry out cerebral angiography which showed the presence of thrombosis of both transverse venous sinuses, no hypercoagulability states were found in the laboratories, the immunological tests carried out for antiphospholipid syndrome were negative, the thrombotic event was associated with the ChAdOx1-S vaccine, later the patient was taken to thrombectomy by Neuroradiology, achieving complete channeling of both transverse venous sinuses. Conclusions: Adverse events associated with vaccination have been described with multiple vaccine agents, this component against COVID-19 is also an event to consider, knowing the pathophysiology of these events is essential to be able to reduce these risks and select the least risky agent. Despite this risk, vaccination remains the only cost-effective measure to reduce the morbidity and mortality associated with COVID-19.

Visceral leishmaniasis (VL)is a fatal disease caused by the protozoa Leishmania infantum for which dogs are the main reservoirs. A vaccine against canine visceral leishmaniasis (CVL) could be an important tool in the control of human and CVL by reducing the infection pressure of L. infantum. Despite the CVL vaccine available on the market, the Brazilian Ministry of Health did not implement the use of it in their control programs. In this sense, there is an urgent need to develop more efficient vaccines. In this study, the association between two polymeric nanoformulations, [poly (D, L-lactic) acid (PLA) polymer] loading Leishmania amazonensis antigens, was evaluated as a potential immunobiological agent against VL using golden hamsters as an experimental model. The results indicated that no significant adverse reactions were observed in animals vaccinated with LAPSmP. LAPSmP presented similar levels of total anti-Leishmania IgG as compared to LAPSmG. The LAPSmP and LAPSmG groups showed an intense reduction in liver and spleen parasitic load by qPCR. The LAPSmP and LAPSmG vaccines showed exceptional results, indicating that they may be promising candidates as a VL vaccine.

Schistosomiasis, a disease historically associated with poverty, lack of sanitation and social inequalities, is a chronic, debilitating parasitic infection, affecting hundreds of millions of people in endemic countries. Although schistosomiasis control approach has shown that chemotherapy is capable of reducing morbidity in humans, rapid re-infection is a reminder that the impact of drug treatment on transmission control or elimination initiatives is marginal. In addition, and regardless of more than two decades of well-executed control activities based on large-scale chemotherapy, the disease is expanding in many areas including Brazil. The development of the Sm14/GLA-SE schistosomiasis vaccine is an emblematic open knowledge innovation that has successfully completed Phase I and Phase IIa clinical trials, with Phase II/III trials underway in the African continent and to be followed in Brazil. Discovery and experimental phases were long term achievements leading to a robust collection of data that are strongly supporting the presently ongoing Clinical Phase. This paper reviews the development of the Sm14 vaccine formulated with GLA-SE (Glucopyranosyl Lipid A), from the earlier experimental developments to clinical trials including the recent status of Phase II studies.

Parental willingness is a prerequisite for childhood immunization. This study evaluated whether parental vaccination readiness and willingness, measured using the modified Japanese 7C Vaccination Readiness Scale, predicted vaccination behavior. In December 2021, 2 months before the approval of COVID-19 vaccination for children aged 5–11 years in Japan, we asked 1,190 parents of children in this age groups about their intention regarding vaccinating their children against COVID-19 using an online modified 7C Vaccination Readiness Scale, consisting of seven components, namely, Confidence, Complacency, Constraints, Calculation, Collective responsibility, Compliance, and Conspiracy. The modified 7C components were analyzed for model fit and association with parental intention using structural equation modeling. The model fit of the modified 7C scale was good (goodness-of-fit index: 0.98), and the factor loadings and model fit for parental readiness were high (standardized factor loadings: 0.84). In January 2024, we asked the same parents about their children's COVID-19 vaccination status (valid responses: 536). The components of the modified 7C scale were compared with actual vaccination behavior. Parents with a low readiness to vaccinate their children against COVID-19 had a high actual non-vaccination rate. The use of the modified 7C scale may assist in the development of childhood vaccination interventions.

Human papillomavirus (HPV) is the most common sexually transmitted infection in the US and the world. Infection with high-risk oncogenic HPV strains have been shown to induce cellular transformation leading to anogenital and oropharyngeal cancers. The HPV vaccine first developed in 2006 for females aged 9-26 years has been demonstrated to be safe and effective in preventing 90% of all HPV associated cancers. However, vaccine hesitancy, misinformation, and barriers to vaccine access has resulted in suboptimal vaccination rates among adolescent populations, especially in rural communities in the South. HPV vaccine coverage in Tennessee is currently below the national average and below the Healthy People 2030 goal of an 80% vaccination rate for individuals 13-17 years old based on recommendation guidelines for up-to-date HPV vaccination status as of 2022. HPV vaccination rates for Tennesseans with private insurance in 2022 was 68% and 38% for those that were insured. Up-to-date HPV vaccination rates for Tennesseans living in urban communities was 58% in 2022 and 46% for those living in rural communities. Overall, HPV associated cancers rates are higher in Tennessee at 12.9/100,000 compared to the overall rate in the US of 11.8/100,000 persons in 2022. Interventions to improve HPV vaccine awareness, education, and access could improve vaccine confidence and uptake especially among rural and uninsured populations in Tennessee. Most recently, the Advisory Committee on Immunization Practices (ACIP) has expanded recommendations for the HPV vaccinations for some individuals 27-45 years who were not vaccinated at a younger age with shared clinical decision-making. The impact of this recommendation on Tennesseans should be examined.

Three autonomous communities have been the ones that, in the 2022-2023 season, anticipated the document approved by the Public Health Commission, recommending influenza vaccination for all children aged 6 to 59 months. The main objective of this work is to evaluate the attitude of healthcare professionals towards the first universal vaccination campaign in our region, as well as the acceptability of the vaccines used and the attitude towards the piloting of school vaccination. Cross-sectional, survey-based, descriptive study. All healthcare professionals involved in the campaign were invited to participate. The 91.9% of surveyed professionals thought that flu vaccination from 6 to 59 months was important or very important. 89.8% had previous experience regarding the intramuscular vaccine. The professionals valued the intranasal vaccine significantly more positively; however, there were no differences when asking for each of the vaccines without comparison. The inhaled vaccine was preferred by 97.5% for the following campaign. Piloted school vaccination showed 75% acceptance. The inhaled vaccine was preferred by most professionals and the piloted school vaccination was highly accepted, and independently associated to the importance of vaccination as considered by physicians, being a medical doctor, and participation in the pilot program.

An important step towards COVID-19 pandemic control is adequate knowledge and adherence to mitigation measures, including vaccination. We assessed the level of COVID-19 knowledge, attitudes, and practices among residents from an urban informal settlement in the City of Nairobi (Kibera), and a rural community in western Kenya (Asembo). A cross-sectional survey was implemented from April to May 2021 among randomly selected adult residents from a population-based infectious diseases surveillance (PBIDS) cohort in Nairobi and Siaya Counties. Factors associated with the level of COVID-19 KAP, were assessed using multivariable regression methods. COVID-19 vaccine acceptance was 83.6% for the participants from Asembo and 59.8% in Kibera. The reasons cited for vaccine hesitancy in Kibera were safety concerns (34.0%), insufficient information available to decide (18.0%), and a lack of belief in the vaccine (21.0%), while the reasons in Asembo were safety concerns (55.0%), insufficient information to decide (26.0%) and lack of belief in the vaccine (11%). Our study findings suggest the need for continued public education to enhance COVID-19 knowledge, attitudes, and practices to ensure adherence to mitigation measures. Urban informal settlements require targeted messaging to improve vaccine awareness, acceptability, and uptake.

Background: COVID-19 booster uptake remained poor among healthcare workers (HCW) despite evidence of improved immunity against Delta and Omicron variants. While most studies used a questionnaire to assess hesitancy, this study aimed to identify factors affecting true booster hesitancy by examining actual vaccine uptake across time. Method: COVID-19 vaccination database records among HCW working at 7 Singaporean public primary care clinics between January to December 2021 were extracted, with gender, profession, place of practice, vaccination type and dates. Time to booster was calculated from the date of vaccination minus date of eligibility. Chi-square test was used to compare relationship between 1st dose and booster hesitancy, Kaplan-Meier method and Log-rank test were adopted to evaluate differences in cumulative booster uptake. Multivariate cox regression was used to investigate predictors for timely booster vaccination. Vaccination rate was charted across time and corroborated with media releases pertaining to legislative changes. Results: 877 of 891 (98.9%) primary care HCW were fully vaccinated, 73.8% of eligible HCW had taken the booster. HCW were less booster hesitant [median 16 (5-31.3) days] compared to the 1st dose [median 39 (13-119.3) days]. 1st dose hesitant HCW were more likely to be booster hesitant (OR=3.66, 95%CI 2.61-5.14). Adjusting for sex, workplace and time to 1st dose, ancillary (HR=1.53, 95%CI 1.03-2.28), medical (HR=1.8, 95%CI 1.18-2.74) and nursing (HR=1.8, 95%CI 1.18-2.37) received boosters earlier compared with administrative staff. No temporal relationship was observed between booster uptake, legislative changes and COVID-19 infection numbers. Conclusion: Vaccine hesitancy among HCW had improved from booster to 1st dose, with timely booster vaccination among medical and nursing staff. Tailored education, risk messaging and strategic legislation might help to reduce delayed booster vaccination.

Pertussis is a vaccine-preventable disease caused by the bacterium Bordetella pertussis. Over the past years, the incidence and mortality of pertussis increased significantly. A possible cause is the switch from whole cell to acellular pertussis vaccines, although other factors may also contribute. To develop future vaccines and improve current vaccination strategies, it is critical to understand factors influencing the generation of immunological memory. We applied high-dimensional flow cytometry to investigate changes in B cells in individuals of different ages and distinct priming backgrounds upon administration of an acellular pertussis booster vaccine. These findings were correlated to vaccine-specific plasma cells and serum Ig levels. Expansion and maturation of plasma cells 7 days post-vaccination was the most prominent cellular change in all age groups, and was most pronounced for more mature IgG1+ plasma cells. Cellular responses were stronger in individuals primed with whole cell vaccine than in individuals primed with acellular vaccine. Moreover, IgG1+ plasma cell expansion weakly correlated with Prn- and PT- specific serum IgG levels. Our study points at plasma cells as a potential early cellular marker of an immune response and contributes to understanding differences in immune responses between age groups and priming backgrounds.

Pseudomonas aeruginosa is a critical healthcare challenge due to its ability to cause persistent infections and the acquisition of antibiotic resistance mechanisms. Lack of preventive vaccines and rampant drug resistance phenomenon has rendered patients vulnerable. As new antimicrobials are in the preclinical stages of development, mining for the unexploited drug targets is also crucial. Here, we designed a chimeric vaccine against P. aeruginosa using a subtractive proteomics approach and identified nine unique enzymes as novel drug targets in PAO1 proteome. A total of five unique proteins were selected as potential vaccine candidates based on essentiality, extracellular localization, virulence, antigenicity, pathway association, protein-protein interaction analysis, hydrophilicity, and low molecular weight. These include two outer membrane porins OprF (P13794) and OprD (P32722), a protein activator precursor pra (G3XDA9), a probable outer membrane protein precursor PA1288 (Q9I456), and a conserved hypothetical protein PA4874 (Q9HUT9). These proteins were further analyzed using a reverse vaccinology approach to identify immunogenic and antigenic T cell and B cell epitopes. The best scoring epitopes qualifying for all set criteria were then further subjected to the construction of a polypeptide multi-epitope vaccine construct with cholera toxin B (CtxB) subunit as an adjuvant. The identified drug targets qualifying the screening criteria were: UDP-2-acetamido-2-deoxy-d-glucuronic acid 3-dehydrogenase WbpB (G3XD23), aspartate semialdehyde dehydrogenase (Q51344), 2-amino-4-hydroxy-6-hydroxymethyldihydropteridine pyrophosphokinase (Q9HV71), 3-deoxy-D-manno-octulosonic-acid transferase (Q9HUH7), glycyl-tRNA synthetase alpha chain (Q9I7B7), riboflavin kinase/FAD synthase (Q9HVM3), aconitate hydratase 2 (Q9I2V5), probable glycosyltransferase WbpH (G3XD85) and UDP-3-O-[3-hydroxylauroyl] glucosamine N-acyltransferase (Q9HXY6). For druggability and pocketome analysis crystal and homology structures of these proteins were retrieved and developed. A sequence-based search was performed in different databases (ChEMBL, Drug Bank, PubChem and Pseudomonas database) for the availability of reported ligands and tested drugs for the screened targets. These predicted targets may provide a basis for the development of reliable antibacterial preventive and therapeutic options against P. aeruginosa.

There is a growing public health need for effective preventive interventions against dengue, and a safe, effective and affordable dengue vaccine against the four serotypes would be a significant achievement for disease prevention and control. Two tetravalent dengue vaccines, Dengvaxia (Sanofi Pasteur) and DENVax (Takeda Pharmaceutical Company), have now completed phase 3 clinical trials. While Dengvaxia resulted in serious adverse events and is restricted to individuals with prior dengue infections, DENVax has shown, at first glance, some encouraging results. Using the available data for the TAK 003 trial, we estimate, via the Bayesian approach, vaccine efficacy (VE) of the post-vaccination surveillance periods. Although better measurement over long time was expected for the second part of the post-vaccination surveillance, variation in serotype-specific efficacy needs careful consideration. Besides observing that individual serostatus prior to vaccination is determinant of DENVax vaccine efficacy, we also compare the VE estimations for 12 and 18 months and we observe that the efficacy is decreasing over time. The comparison of efficacies over time is informative and very important, bring up the discussion of the role of temporary cross-immunity in dengue vaccine trials and the impact of serostatus prior to vaccination in the context of dengue fever epidemiology.

Background: Respiratory syncytial virus (RSV) is a leading cause of acute lower respiratory infection globally. There are vaccines in pipeline to prevent it but a systematic review on immunogenicity and safety of vaccine is lacking. Methods: This systematic review of RSV vaccine clinical trials was undertaken using 4 databases. Searches were conducted using both controlled vocabulary terms such as ‘Respiratory Syncytial Virus, Human’, ‘Respiratory Syncytial Virus Infections’, ‘Respiratory Syncytial Virus Vaccines’, ‘Immunization’, ‘Immunization Programs’ and ‘Vaccines’ and corresponding text word terms. The searches for published papers were limited to clinical trials published from January 2000 to August 6th, 2018. RSV infection case was defined as RSV associated medically attended acute respiratory illness (MAARI) or RSV infection by serologically-confirmed test (Western Blot) during the RSV surveillance period. We calculated the relative risk of each vaccine trial with RSV infection case. Results: Of 4395 publications, 24 were included and data were extracted covering 4 major types of RSV vaccine candidates, these being live-attenuated/chimeric (n=9), recombinant-vector (n=10), subunit (n=1) and nanoparticle vaccines (n=4). For RSV infection cases, 7 trials were involved and none of them showed a vaccine-related increased MAARI during RSV surveillance season. Conclusion: LID ∆M2-2, MEDI M2-2, and RSVcps2 (live-attenuated) were considered the most promising vaccine candidates in infant and children. In the elderly, a nanoparticle F vaccine candidate was considered as a potential effective vaccine. Although no promising vaccine was identified from pregnant-women test, RSV F-024 subunit vaccine candidate and an RSV F nanoparticle vaccine showed encouraging results in healthy non-pregnant women.

Coronavirus disease 2019 (COVID-19) is an emerging infectious disease that was first reported in Wuhan, China and has subsequently spread worldwide. In the absence of any antiviral or immunomodulatory therapies, the disease is spreading at an alarming rate. 5 to 10% of recovered patients in Wuhan test positive again; this suggest that for controlling COVID-19, vaccines may be better option than drugs. A clinical trial to evaluate an anti-COVID-19 vaccine has started recently. However, its efficacy and potency have to be evaluated and validated. As an alternative, we are presenting a first-of-its-kind, designed multi-peptide subunit based epitope vaccine against COVID-19. The vaccine construct comprise an adjuvant, CTL, HTL, and B-cell epitopes joined by linkers. The vaccine is non-toxic, non-allergenic, thermostable and immunogenic with the capability to elicit a humoral and cell-mediated immune response. The findings are validated with high-end computation-based methods. This unique vaccine is made up of 33 highly antigenic epitopes from three proteins that have a prominent role in host receptor recognition, viral entry, and pathogenicity. We advocate this vaccine must be synthesized and tested urgently as public health priority.

Appropriate vaccine selection is crucial in the control of foot-and-mouth disease (FMD). Vaccination can prevent clinical disease and reduces viral shedding, but there is a lack of cross-protection between the seven serotypes and their sublineages, making the selection of an adequately protective vaccine difficult. Since the exact composition of their vaccines is not consistently disclosed by all manufacturers, incompatibility of the strains used for vaccination with regionally circulating strains can cause vaccination campaigns to fail. Here, we present a deep sequencing approach for polyvalent inactivated FMD vaccines that can identify all component strains by their genome sequences. The genomes of all strains of a commercial pentavalent FMD vaccine were de-novo assembled and the vaccine composition determined semi-quantitatively. The genome assembly required high stringency parameters to prevent misassemblies caused by conserved regions of the genome shared by related strains. In contrast, reference-guided assembly is only recommended in cases where the number of strains is previously known and appropriate reference sequences are available. The presented approach can be applied not only to any inactivated whole-virus FMD vaccine, but also to vaccine quality testing in general and allows for better decision-making for vaccines with unknown composition.

This study aimed to evaluate the mixed and homogeneous application of the inactivated SARS-CoV-2 vaccine CoronaVac (CV) and the mRNA vaccine BNT162b2 (BNT). This prospective cohort study included 235 health care workers, who had received two prime shots with CoronaVac. They were divided into three cohorts after the third month: Cohort-I (CV/CV); Cohort-II (CV/CV/CV) and Cohort-III (CV/CV/BNT). Anti-S-RBD-IgG and total an-ti-spike/anti-nucleocapsid-IgG antibody concentrations were examined in vaccinated health workers at the 1st, 3rd and 6th months following the second dose of the vaccination. The mean age of 235 health care workers who participated in the project was 39.51±10.39 (min-max: 22-64). At the end of the 6th month, no antibodies were detected in 16.7% of Cohort-I participants, and anti-S-RDB IgG levels showed a decrease of 60% compared to the levels of the 3rd month. The antibody concentrations of the 6th month were found to have increased by an average of 5.13 times compared to the 3rd-month levels in the Cohort-II and 20.4 times in Cohort-III. The heterologous vaccination strategy “CoronaVac and BNT162b2 regimen” is able to induce a stronger immunity and it will help remove inequalities in the developing world where CoronaVac was the initial prime.

Background: The Shingrix vaccine helps prevent shingles and its complications in adults 50 and older. While minor side effects are common, severe adverse reactions are thought to be rare, and long-term side effects are not well documented. Case Presentation: A 50-year-old woman with Crohn's disease developed joint pain, effusion, and neurological symptoms such as numbness and tingling shortly after receiving the first dose of Shingrix. Symptoms waxed and waned but persisted for over a year despite anti-inflammatories and specialist referrals. Diagnostic imaging and labs were unrevealing. Conclusion: This case of prolonged somatic and neurological symptoms associ-ated temporally with Shingrix administration reinforces the critical need for thorough pharma-covigilance and investigation of possible long-term adverse vaccine reactions. Provider documen-tation and reporting of individual experiences can help improve the detection of rare vaccine-related risks, elucidate potential risk factors, and refine safety screening. Diligent monitoring and research into longitudinal vaccine outcomes remain paramount, especially following recent emergency au-thorizations.

Influenza is well-known to have a considerable influence on healthcare system, therefore, vaccination plays a significant role in dealing with severe consequences. Close attention is paid to the development of tetravalent adjuvanted vaccines, containing antigens of two influenza A subtypes (H1N1, H3N2) and two influenza B subtypes (Victoria, Yamagata) to increase the effectiveness of influenza prevention. In this work we present the results of pre-clinical study of innovative subunit tetravalent candidate influenza vaccine, with addition of betulin as adjuvant, TetraFluBet. The study was conducted using female BALB/c mice, male and female mongrel rats and guinea pigs. TetraFluBet and commercially available vaccines were injected intraperitoneally twice in a 14-day interval after intranasal infection with 5LD50 and 10LD50. Chronic toxicity was assessed by immunohistochemistry of extracted organs and by hematological and biochemical blood parameters. Protectivity and immunogenicity were evaluated using hemagglutination inhibition and microneutralization with MDCK assays. Chronic toxicity study did not reveal any side effects of candidate TetraFluBet vaccine on both rats and guinea pigs. One vaccination dose of TetraFluBet provided 100% protectivity against all 4 influenza subtypes and significantly increased neutralizing antibody activity in response to immunization of influenza subtypes. Pre-clinical candidate vaccine TetraFluBet confirmed its safety along with specific activity, showed high immunogenicity and can be recommended for further clinical studies.

Abstract: Background: The vaccination status of patients with inflammatory bowel disease (IBD) should be investigated before starting any treatment, and patients eventually vaccinated against vaccine preventable diseases (VPDs). Vaccination rates in patients with IBD are known to be suboptimal. The aim of this study was to investigate the vaccination coverage, attitude towards vaccinations and its possible determinants among a national cohort of IBD patients. Methods: An anonymous web-based questionnaire was sent by the Italian IBD patients’ association (AMICI) in February 2021. Previous vaccination status and patients’ attitude towards vaccinations were rec-orded. The factors influencing their attitudes were examined using crude and adjusted odds ratios (AdjORs) with 95% confidence intervals (CIs). Results: Among 4039 patients invited, 1252 patients (including 729 women, median age 47.7 [37–58]) completed the questionnaire, a response rate of 25.3%. Patients declared being vaccinated against: 74.1% tetanus, 67.7% flu (last season), 43.3% MMR, 37.1% HBV, 29.1% pneumococcus, 20% meningitis, 16% HAV, 15.3% VZV, 7.6% HPV. Two hundred and fifty-nine (20.7%) did not remember every previous vaccination. One thousand one hundred and twelve (88.8%) expressed a positive attitude towards vaccination, 91 (7.3%) were indifferent, 49 (3.9%) reported being opposed to vaccinations. The belief of possible return of VPDs with decline of vaccination coverage rates was the factor most strongly related to a positive at-titude towards vaccinations (AdjOR 5.67, 95% CI 3.45-9.30, p-value <0.001). Conclusions: A low vaccination rate against some VPDs was found among a national cohort of patients with IBD, despite a generally positive attitude towards vaccinations.

This study focuses on cardiovascular effects, particularly myocarditis and pericarditis events, after BNT162b2 mRNA COVID-19 vaccine injection in Thai adolescents. This prospective cohort study enrolled students from two schools aged 13–18 years who received the second dose of the BNT162b2 mRNA COVID-19 vaccine. Data including demographics, symptoms, vital signs, ECG, echocardiography and cardiac enzymes were collected at baseline, Day 3, Day 7, and Day 14 (optional) using case record forms.We enrolled 314 participants; of these, 13 participants were lost to follow up, leaving 301 participants for analysis. The most common cardiovascular effects were tachycardia (7.64%), shortness of breath (6.64%), palpitation (4.32%), chest pain (4.32%), and hypertension (3.99%). Seven participants (2.33%) exhibited at least one elevated cardiac biomarker or positive lab assessments. Cardiovascular effects were found in 29.24% of patients, ranging from tachycardia, palpitation, and myopericarditis. Myopericarditis was confirmed in one patient after vaccination. Two patients had suspected pericarditis and four patients had suspected subclinical myocarditis. Conclusion: Cardiovascular effects in adolescents after BNT162b2 mRNA COVID-19 vaccination included tachycardia, palpitation, and myocarditis. The clinical presentation of myopericarditis after vaccination was usually mild, with all cases fully recovering within 14 days. Hence, adolescents receiving mRNA vaccines should be monitored for side effects. Clinical Trial Registration: NCT05288231

African swine fever (ASF) is a pandemic threat to the global pig industry and wild suids. A safe and efficacious vaccine could monumentally assist in disease eradication. In the past years, promising live attenuated vaccine candidates emerged in proof-of-concept experiments, among them, “ASFV-G-∆MGF”. In our study, we tested the vaccine candidate in three animal experiments intramuscularly in domestic pigs one orally in wild boar. Further, a macrophage-grown vaccine virus and a virus grown on permanent cells could be employed. Irrespective of the production system of vaccine virus, a two-dose intramuscular immunization could induce close to sterile immunity with full clinical protection against challenge infection. After oral immunization, 50% of the vaccinees seroconverted and all responders were completely protected against subsequent challenge. All non-responders developed ASF upon challenge with two acute lethal infections and two mild and transient courses. The latter results show a lower efficiency after oral administration that would have to be taken into consideration when designing vaccination-based control measures. Our findings suggest that “ASFV-G-∆MGF” could help to contain the disease under an appropriate vaccination campaign. Further research is needed to characterize safety aspects and define possible improvements of oral efficiency.

Social media HPV vaccination interventions show promise for increasing HPV vaccination rates. An important consideration for the implementation of effective interventions into real-world practice in the translation potential, or external validity, of the intervention. To this end, we conducted a systematic literature review to describe the current body of evidence regarding the external validity of social media HPV vaccination-related interventions. Constructs related to external validity were based on the RE-AIM (reach, effectiveness, adoption, implementation, maintenance) framework. Seventeen articles published between 2006 and 2020 met inclusion criteria. Three researchers independently coded each article using a validated RE-AIM (reach, effectiveness/efficacy, adoption, implementation, maintenance) framework. Discrepant codes were discussed with a fourth reviewer to gain consensus. Of these 17 studies, three were pilot efficacy studies, 10 were RCTs to evaluate effectiveness, one was a population-based study, and three did not explicitly state which type of study was conducted. Reflecting this distribution of study types, across all studies the mean level of reporting RE-AIM dimensions varied with reach recording 90.8%, effectiveness (72.1%), adoption (40.3%), implementation (45.6%), and maintenance (26.5%). This review suggests that while the current HPV vaccination social media-driven interventions provide sufficient information on internal validity (reach and effectiveness), few have aimed to gather data on external validity needed to translate the interventions into real world implementation. Our data suggest that implementation research is needed to move HPV vaccination-related interventions into practice. Included in this review are recommendations for enhancing the design and reporting of these HPV vaccination social media-related interventions.

Various studies indicate that vaccination, especially with pneumococcal vaccines, protects against symptomatic cases of SARS-CoV-2 infection and death. This paper explores the possibility that pneumococcal vaccines in particular, but perhaps other vaccines as well, contain antigens that might be cross-reactive with SARS-CoV-2 antigens. Comparison of the glycosylation structures of SARS-CoV-2 with the polysaccharide structures of pneumococcal vaccines yielded no obvious similarities. However, while pneumococcal vaccines are primarily composed of capsular polysaccharides, some are conjugated to CRM197, a modified diphtheria toxin, and all contain about three percent protein contaminants, including the pneumococcal surface proteins PsaA, PspA and probably PspC. All of these proteins have very high degrees of similarity, using very stringent criteria, with several SARS-CoV-2 proteins including the spike protein, membrane protein and replicase 1a. CRM197 is also present in Hib and meningitis vaccines. Equivalent similarities were found at lower rates, or were completely absent, among the proteins in diphtheria, tetanus, pertussis, measles, mumps, rubella, and poliovirus vaccines. Notably, PspA and PspC are highly antigenic and new pneumococcal vaccines based on them are currently in human clinical trials so that their effectiveness against SARS-CoV-2 disease is easily testable.

Newcastle Disease (ND) remains a critical disease affecting poultry in sub-Saharan Africa. In some countries, repeated outbreaks have a major impact on local economies and food security. Recently, we developed an adenovirus-vectored vaccine encoding the Fusion protein from an Ethiopian isolate of Newcastle Disease Virus (NDV). The adenoviral vector was designed and a manufacturing process developed in the context of the Livestock Vaccine Innovation Fund initia-tive funded by the International Development Research Centre (IDRC) of Canada. The industrial-ly-relevant recombinant vaccine technology platform is being transferred to the National Veteri-nary Institute (Ethiopia) for veterinary applications. Here, we demonstrate that the instillation of the adenoviral vector through the nasal cavity can confer protection to chickens against a lethal challenge with NDV. A manufacturing process using HEK293 suspension cells cultured in stirred-tank bioreactor for the vaccine production is proposed. Taking into consideration supply chain limitations, options for serum-free media selection have been evaluated. A streamlined downstream process including a filtration, an ultrafiltration and a concentration step was de-veloped. With high volumetric yields (infectious titers up to 5 x 109 TCID50/mL) in the culture su-pernatant, the final formulations were prepared at 1010 TCID50/mL, either in liquid or lyophi-lized forms. The liquid formulation was suitable and safe for mucosal vaccination and was sta-ble for 1 week at 37˚C. Both liquid and lyophilized formulations were stable after 6 months of storage at 4˚C. Overall, a manufacturing process for adenovirus vectored vaccine was developed and protective doses were determined using a convenient route of delivery. Formulation and storage conditions were established, and quality control protocols were implemented.

Infections with Flavobacterium oreochromis pose risks to Colossoma macropomum production. Since no treatment exists, prophylaxis through vaccination is the only form for disease control. The enzyme-linked immunosorbent assay (ELISA) is widely used in aquaculture to assess animal immunity and mainly to validate vaccination protocols. The method based on the use of immunoglobulin Y (IgY) is an alternative to consider due to its advantages over antibodies produced by small mammals. This study aimed to standardize an indirect ELISA (iELISA) protocol to validate the immunization of C. macropomum against F. oreochromis. A hen and fish were immunized to obtain anti-C. macropomum and anti-F. oreochromis antibodies, which were used to standardize the test. The iELISA was composed of the inactivated bacteria in the coating step, C. macropomum anti-Flavobacterium oreochromis as the primary antibody, and anti-C. macropomum IgY as the secondary antibody. The results demonstrate that the highest antibody titers were among the immunized groups, which were bacterin + adjuvant and bacterin. The iELISA enabled the detection of antibodies produced by C. macropomum, which were mediated by IgY specificity.

The leading cause of gastroenteritis in children under the age of five is rotavirus infection, accounting for 37% of diarrhoeal deaths in infants and young children globally. Oral rotavirus vaccines have been widely incorporated into national immunisation programs, but whilst these vaccines have excellent efficacy in high-income countries, they protect less than 50% of vaccinated individuals in low- and middle-income countries. In order to facilitate the development of improved vaccine strategies, a greater understanding of the immune response to existing vaccines is urgently needed. However, the use of mouse models to study immune responses to human rotavirus strains is currently limited as rotaviruses are highly species-specific and replication of human rotaviruses is minimal in mice. To enable characterisation of immune responses to human rotavirus in mice, we have generated chimeric viruses that combat the issue of rotavirus host range restriction. Using reverse genetics, the rotavirus outer capsid proteins (VP4 and VP7) from either human or murine rotavirus strains were encoded in a murine rotavirus backbone. Neonatal mice were infected with chimeric viruses and monitored daily for development of diarrhoea. Stool samples were collected to quantify viral shedding, and antibody responses were comprehensively evaluated. We demonstrated that chimeric rotaviruses were able to efficiently replicate in mice. Moreover, the chimeric rotavirus containing human rotavirus outer capsid proteins elicited a robust antibody response to human rotavirus antigens, whilst the control chimeric murine rotavirus did not. This chimeric human rotavirus therefore provides a new strategy for studying human rotavirus-specific immunity, and could be used to investigate factors causing variability in rotavirus vaccine efficacy. This small animal platform therefore has the potential to test the efficacy of new vaccines and antibody-based therapeutics.

Hepatitis C virus (HCV) is a major medical health burden and leading cause of chronic liver disease and cancer worldwide. More than 58 million people are chronically infected with HCV, with 1.5 million new infections occurring each year. An effective HCV vaccine is a major public health and medical need as recognized by the World Health Organization. However, due to the high variability of the virus and its ability to escape the immune response, HCV rapidly accumulates mutations making a vaccine a formidable challenge. An effective vaccine must elicit broadly neutralizing antibodies (bnAbs) in a consistent fashion. After decades of studies from basic research through clinical development, the antigen of choice is considered to be the E1E2 envelope glycoprotein due to conserved, broadly neutralizing antigenic domains located in the constituent subunits of E1, E2, and the E1E2 heterodimeric complex itself. The challenge has been elicitation of robust humoral and cellular responses leading to broad virus neutralization due to the relatively low immunogenicity of this antigen. In view of this challenge, structure-based vaccine design approaches to stabilize key antigenic domains have been hampered due to the lack of E1E2 atomic-level resolution structures to guide them. Another challenge has been development of a delivery platform in which a multivalent form of the antigen can be presented in order to elicit a more robust anti-HCV immune response. Recent nanoparticle vaccines are gaining prominence in the field due to their ability to facilitate a controlled multivalent presentation and trafficking to lymph nodes, where they can interact with both the cellular and humoral components of the immune system. This review focuses on recent advances in understanding the E1E2 heterodimeric structure to facilitate a rational design approach and the potential for development of a multivalent nanoparticle-based HCV E1E2 vaccine. Both aspects are considered important in the development of an effective HCV vaccine that can effectively address viral diversity and escape.

Nanotechnology has provided an opportunity for unparalleled development of the treatment of various severe diseases. The unique properties of nanoparticles offer a promising strategy in enhancing antitumor immunity by enhancing immunogenicity and presentation of tumor autoantigens for cancer immunotherapy. Polymeric, liposomal, carbon or silica-based nanoparticles are among those with major immunomodulatory roles in various cancer treatments. Cancer vaccines, in particular digestive cancer vaccines have been researched and developed on nanotechnological platforms. Due to their safety, controlled release, targeting of dendritic cells(DCs) and improved antigen uptake, as well as enhanced immunogenicity, nanoparticles have been used as carriers, as adjuvants for increased effect at the tumor level, for their immunomodulating effect, or for targeting tumor microenvironment, increasing tumor immunogenicity and reducing tumor inflamatory response. This review looks at digestive cancer vaccines developed on nanoparticle platforms and the impact nanoparticles have on the effects of these vaccines.

In response to the COVID-19 crisis, decisionmakers in countries around the world adopted policies such as lockdowns, mask requirements, and once vaccines became available, vaccine mandates and vaccine passports. However, political polarization and differences in risk perceptions in the populous generated strong support for and opposition to such measures. This research identifies the factors with support for and against vaccine mandates and vaccine passports. An online survey of COVID-19 health experiences in the United States population was conducted. The survey collected information regarding potential reasons for why respondents might favor or oppose COVID-19 vaccine mandates and vaccine passports, including experiences with COVID-19 illness and COVID-19 vaccinations by respondents and those in their social circles. Analysis using a Logit regression technique was conducted to identify factors influencing the likelihood of opposing vaccine mandates and vaccine passports. The survey was completed by 2,840 participants between December 18 and 23, 2021. Respondents who knew someone who experienced a health problem following vaccination were more likely to oppose vaccine mandates (OR: 2.040, 95% CI: 1.635-2.254, and vaccine passports (OR: 1.691, 95% CI: 1.361-12.101)) Twenty-two percent (612 of 2,840) of respondents reported that they knew at least one person who had experienced a health problem following COVID-19 inoculation. Perceptions of vaccine safety based on personal experiences appear to be an important determinant of opposition to vaccine mandates and vaccine passports.

Porcine epidemic diarrhea (PED) is a swine wasting disease caused by coronavirus infection. It causes great economic damage to the swine industry worldwide. Despite the continued use of vaccines, PED outbreaks continue, highlighting the need to review the effectiveness of current vaccines and develop additional vaccines based on new platforms. Here, we review existing vaccine technologies for preventing PED and highlight promising technologies that may help control PED virus in the future.

Vaccine hesitancy substantially impacts global vaccination rates. During the COVID-19 pandem-ic in Germany, vaccination uptake exhibited considerable regional disparities. To assess the fac-tors contributing to this variation, we examined the influence of sociodemographic variables on COVID-19, COVID-19 booster, and influenza vaccinations within a cohort of 37,078 participants from 13 German federal states in the digital health cohort study, DigiHero. Our findings re-vealed variations in vaccination rates based on sociodemographic factors. However, these fac-tors had limited explanatory power regarding regional differences in vaccine uptake. In contrast, we found substantial correlations between regional support of specific parties during last local elections and the vaccination uptake at Landkreis-level. In conclusion, sociodemographic factors alone did not suffice to explain the regional disparities in vaccine uptake. Political stances can play a major role, but the current investigation did not assess the individual political orienta-tion, but used only ecological approach.

Hispanic/Latino communities have suffered a disproportionate burden due to the COVID-19 pandemic. Although Puerto Rico has one of the highest COVID-19 primary series vaccination rates nationwide, this estimate contrasts with the low uptake of booster doses (32.7%). This study aimed to assess health belief correlates of COVID-19 vaccine booster uptake. PR-CEAL recruited 787 participants via an online survey between December 2021 and January 2022. Sociodemographic characteristics and questions framed using the Health Belief Model were assessed. Analyses included adjusted Poisson regression models to estimate prevalence ratios (PR) of booster refusal. Overall, 22% of participants planned (10%) or refused (12%) the vaccine booster. Participants with lower income [PR=1.92; 95%CI=1.30, 2.84], in disagreement with vaccine benefits [PR=4.16; 95%CI=3.06, 5.64], and in agreement with booster concerns [PR=2.93; 95%CI=2.12, 4.04], efficacy [PR=2.76; 95%CI=2.00, 3.82], and safety [PR=2.97; 95%CI=2.15, 4.08] were significantly more likely to refuse the booster. Booster vaccination refusal was associated with lower perceived vaccine benefits and higher barriers among adults in Puerto Rico. Results informed CEAL team intervention strategies for public health campaigns to increase booster vaccine uptake.

Improving antigen presentation is crucial for the success of immunization strategies. Yeasts are classically used as biofactories to produce recombinant proteins and are efficient vehicles for the delivery of vaccine antigens, besides present adjuvants properties. Despite the absence of epidemic outbreaks, several vaccine approaches continue to be developed for Zika virus infection. These prophylactic strategies are fundamental given the severity of clinical manifestations, mainly due to viral neurotropism. The present study aimed to evaluate in vivo the immune response induced by P. pastoris recombinant strains displaying epitopes of the Envelope (ENV) and NS1 ZIKV proteins. Intramuscular immunization with heat-attenuated yeast enhanced the secretion of IL-6, TNF-α, and IFN-γ, besides activation of CD4+ and CD8+ T cells, in BALB/c mice. P. pastoris displaying ENV epitopes induced a more robust immune response, increasing immunoglobulin production, especially IgG isotypes. Both proposed vaccines showed the potential to induce immune responses without adverse effects, confirming the safety of administering P. pastoris as a vaccine vehicle. Here we demonstrated, for the first time, the evaluation of a vaccine against ZIKV based on a multiepitope construct, using yeast as a vehicle, reinforcing the applicability of P. pastoris as a whole yeast cell vaccine.

Despite the remarkable success of SARS CoV-2 vaccines, the rise of variants, some of which are more resistant to the effects of vaccination, highlights the potential need for additional COVID-19 vaccines. We used the Multiple Antigen Presenting System (MAPS) technology, in which proteins are presented on a polysaccharide polymer to induce antibody, Th1, Th17 and CD8+ T cell responses, to engineer a novel vaccine targeting SARS CoV-2. This vaccine contains a fragment of the spike (S) protein receptor-binding domain (RBD) sequence of the original D614G strain and was used to immunize nonhuman primates (NHP) for assessment of immunological responses and protection against SARS CoV-2 challenge. The SARS CoV-2 MAPS vaccine generated robust neutralizing antibodies as well as Th1, Th17 and cytotoxic CD8 T-cell responses in NHPs. Furthermore, MAPS-immunized NHPs had significantly lower viral loads in the nasopharynx and lung compared to control animals. Taken together, these findings support the use of the MAPS platform to make a SARS CoV-2 vaccine. The nature of the platform also could enable its use for the inclusion of different variants in a single vaccine.