ARTICLE | doi:10.20944/preprints202012.0074.v1
Subject: Life Sciences, Biochemistry Keywords: maternal vaccination; autogenous inactivated vaccine; transfer of immunity; humoral immune response; cell-mediated immune response; T cells; PRRSV; swine; IFN-γ producing B cells; CD4 TEMRA cells
Online: 3 December 2020 (09:02:58 CET)
Maternal-derived immunity is a critical component for survival and success of offspring in pigs to protect from circulating pathogens like Type 2 Porcine Reproductive and Respiratory Syndrome Virus (PRRSV-2). The purpose of this study was to investigate the transfer of anti-PRRSV immunity to piglets from gilts that received modified-live virus (MLV) alone (TRT 0), or in combination with one of two autogenous inactivated vaccines (AIVs, TRT 1+2). Piglets from these gilts were challenged with the autogenous PRRSV-2 strain at two weeks of age and their adaptive immune response (IR) was evaluated until 4 weeks post inoculation (wpi). The systemic humoral and cellular IR was analyzed in the pre-farrow gilts, and in piglets, pre-inoculation, and at 2- and 4-wpi. Both AIVs partially protected the piglets with reduced lung pathology and increased weight gain; TRT 1 also lowered piglet viremia best explained by the AIV-induced production of neutralizing antibodies in gilts and their transfer to the piglets. In piglets, pre-inoculation, the main systemic IFN-γ producers were CD21α+ B cells. From 0 to 4 wpi, the role of these B cells declined and CD4 T cells became the primary systemic IFN-γ producers. In lungs, CD8 T cells were the primary and CD4 T cells the secondary IFN-γ producers including a novel subset of porcine CD8α-CCR7- CD4 T cells, potentially terminally differentiated CD4 TEMRA cells. In summary, this study demonstrates that maternal AIV vaccination can improve protection of pre-weaning piglets against PRRSV-2; it shows the importance of transferring neutralizing antibodies to piglets; and it introduces two novel immune cell subsets in pigs – IFN-γ producing CD21α+ B cells and CD8α-CCR7- CD4 T cells.
ARTICLE | doi:10.20944/preprints202008.0622.v1
Subject: Life Sciences, Biochemistry Keywords: Serology; Seroprevalence; Humoral response; COVID-19; serosurvey; epidemiology
Online: 27 August 2020 (12:47:12 CEST)
Seroprevalence studies suggest that the number of PCR-confirmed COVID-19 cases is significantly smaller than the true number of infections. I study logintidual seroprevalence data from 7 sites across the US, from early April 2020 to June 27. I show that not only COVID-19 seroprevalence does not seem to increase over time, there is no clear association between the number of cases reported during a period and the change in seroprevalence during the same time. I conclude that as they are, seroprevalence studies can only be used in the qualitative sense and distinguish between populations with no COVID-19 exposure, to those populations where the virus had already started spreading.
ARTICLE | doi:10.20944/preprints201805.0466.v2
Subject: Life Sciences, Immunology Keywords: influenza; serum; IgG; humoral antibody; original antigenic sin; hemagglutinin
Online: 6 July 2018 (07:53:32 CEST)
The first exposure to influenza is thought to impact subsequent immune responses later in life. The consequences of this can be seen during influenza epidemics and pandemics with differences in morbidity and mortality for different birth cohorts. There is a need for better understanding of how vaccine responses are affected by early exposures to influenza viruses. In this analysis of hemagglutination inhibition (HI) antibody responses in two cohorts of military personnel we noticed differences related to age, sex, prior vaccination, deployment and birth year. These data suggest that HI antibody production, in response to influenza vaccination, is affected by these factors. The magnitude of this antibody response is associated with, among other factors, the influenza strain that circulated following birth.
ARTICLE | doi:10.20944/preprints202209.0101.v1
Subject: Medicine & Pharmacology, General Medical Research Keywords: COVID-19; hemodialysis; vaccination; cellular immunity; humoral immunity; adverse reactions
Online: 7 September 2022 (05:14:06 CEST)
Most studies on vaccines of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have focused on antibody, but cellular immunities are also critical. We aimed to evaluate the immune reactions of hemodialysis (HD) patients after the administration of the booster dose from the perspective of both humoral and cellular immunities. Hemodialysis patients (HD group) and age- and sex-matched non-dialysis individuals (control group) receiving three doses of BNT162b2 vaccine were measured for anti-SARS-CoV-2 immunoglobulin (IgG) and T-SPOTⓇ.COVID test (T-SPOT) before, 3 weeks, and 3 months after the booster dose. The HD group had significantly higher SARS-CoV-2 IgG levels 3 weeks and 3 months after the booster dose than the control group, although both groups had no difference in SARS-CoV-2 IgG levels before the booster dose. Moreover, the HD group had significantly higher T-SPOT levels before and 3 weeks after the booster dose than the control group, but the difference was not significantly different 3 months after the booster dose. Furthermore, the incidence rates of local and systemic adverse reactions were significantly higher in the HD group than in the control group. HD patients obtained higher SARS-CoV-2 IgG levels and SARS-COV-2-specific T-cell responses after the booster dose than control.
ARTICLE | doi:10.20944/preprints202106.0650.v1
Subject: Medicine & Pharmacology, Allergology Keywords: SARS-CoV-2 vaccine; cellular and humoral immunogenicity; DNA vaccine
Online: 28 June 2021 (13:40:25 CEST)
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.
ARTICLE | doi:10.20944/preprints202207.0422.v1
Subject: Life Sciences, Immunology Keywords: cystic fibrosis; SARS-CoV-2; Covid-19, vaccine; antibody response; humoral response
Online: 27 July 2022 (13:29:14 CEST)
During the SARS-CoV-2 vaccination campaign, people with CF (pwCF) were considered a clinically vulnerable population. However, data on immunogenicity of anti-SARS-CoV-2 vaccines in pwCF are lacking. We conducted a prospective study enrolling all patients aged >12 and followed-up in our CF centre, who received two doses of the BNT162b2 vaccine in March-October 2021. They underwent a blood sample for quantification of antibodies to the SARS-CoV-2 spike protein receptor binding domain immediately before receiving the first dose and after 3 and 6 months from the second dose. We enrolled 143 patients (median age: 21 years, range: 13-38); of whom 16 had a previous infection. Median antibody titer (interquartile range) after 3 months from vaccination was 1288 U/mL (730-2115) and decreased to 918 U/mL (534-1488) after 6 months (P<0.0001). Median values were higher among previously infected patients as compared to those naïve to SARS-CoV-2 (9107 vs 1229 U/mL at 3 months and 4810 vs 829 U/mL at 6 months, P<0.0001) with no significant differences in the rate of decline over time (P=0.135). All pwCF mounted an antibody response after two-doses of BNT162b2 vaccine that waned at 6 months from vaccination. Age ≥30 years and use of inhaled corticosteroids were associated with a lower humoral response.
REVIEW | doi:10.20944/preprints201909.0306.v1
Subject: Life Sciences, Immunology Keywords: influenza virus; humoral response; hemagglutinin (HA) of influenza virus; broad neutralizing antibody(bnAb); heterosubtypic immunity of influenza; original antigenic sin "OAS"; "universal" influenza vaccine; protein microarray assay; mPLEX-Flu assay; multiple dimensional assays (MDA))
Online: 27 September 2019 (08:34:56 CEST)
The human antibody response to influenza virus infection or vaccination is as complicated as it is essential for protection against flu. The constant antigenic changes of the virus to escape human herd immunity hinder the yearly selection of vaccine strains since it is hard to predict which virus strains will circulate for the coming flu season. A "universal" influenza vaccine that could induce broad cross-influenza subtype protection would help to alleviate this burden. However, the human antibody response is intricate and often obscure, with factors like antigenic seniority or original antigenic sin "OAS", and back-boosting ensuring that each person mounts a unique immune response to infection or vaccination with any new influenza virus strain. Notably, the effects of existing antibodies on cross-protective immunity after repeated vaccinations are unclear. More research is needed to characterize the mechanisms at play, but traditional assays such as hemagglutinin inhibition (HAI) and microneutralization (MN) are excessively limited in scope and too resource-intensive to effectively meet this challenge. In the past ten years, new multiple dimensional assays (MDAs) have been developed to help overcome these problems by simultaneously measuring antibodies against a large panel of influenza hemagglutinin (HA) proteins with a minimal amount of sample in a high throughput way. MDAs will likely be a powerful tool for accelerating the study of the humoral immune response to influenza vaccination and the development of a universal influenza vaccine.