Beliefs, Attitudes and Behaviors of Healthcare Professionals Regarding Seasonal Influenza Vaccination: An Umbrella Review

1. Introduction

Influenza is a transmissible disease which is responsible for seasonal epidemics around the world. It poses a considerable burden to many populations, but older people and children are at higher risk of severe infection. The most effective protective intervention against influenza viruses is seasonal vaccination. Vaccination is responsible for the reduction of severe cases. It also limits the transmission of influenza inside the community as it is more difficult for one person to be infected by others and vice-versa [1]. The World Health Organization states that if vaccination was utilized to the maximum capacity 3,5 - 5 million deaths from transmissible diseases like influenza could be prevented [2]. Another important benefit of vaccination is that it is cost-efficient and thus can be a viable and sustainable strategy of primary prevention for the management of transmissible diseases in developing countries [3].

Particularly, in the case of influenza, global data indicate that vaccination coverage in the general population is lower than expected. In many developing countries, the percentage of the general population which is vaccinating regularly is less than 2%. This is true for China as well. [4]. In developed countries in Europe and America, the percentages of vaccination coverage are slightly higher than 50% but still lower than the recommended. In Greece, the vaccination percentages are presenting an increase in the last years but are still insufficient with recent data showing vaccination coverage to be lower than 30% [5]. Almost half of the elderly get vaccinated regularly. Taking into consideration the fact that they are in greater danger, it is reasonable that this percentage is considered low [6].

But why are flu vaccines so important? Vaccination is vital for influenza as it can reduce the risk of transmission up to 40-60% Influenza targets mainly school-aged children usually during autumn and winter [7]. Its symptoms and severity as well as hospitalizations and deaths present variance and heterogeneity [8]. Influenza epidemics have caused 3 - 5 million cases and 290,000-650,000 deaths related to respiratory conditions worldwide. Most of the deaths occur to people older than the age of 65 years-old [4]. It is also important to highlight that almost all deaths in children younger than the age of 5 years-old occur in low and middle-income countries [9].

Health systems around the world face influenza epidemics each year. For example, in the United States of America it is estimated that 30% of the population could be infected due to the many variants of influenza viruses. It is also estimated that, in case of a future influenza pandemic, 90 million people could be infected in the United States of America only. Available data from previous battles against influenza in combination with the annual USA national action plan for prevention and treatment indicate that nearly 40 million people will need outpatient care, 1 to 10 million will need hospitalization, up to 1,5 million will need intensive care unit admissions, over half a million will need mechanical ventilation support and up to 2 million deaths are expected [10]. The example of the USA is representative of all developed countries around the world. In developing countries, unfortunately, the situation regarding influenza is even worse. Due to the lack of infrastructure in terms of hospitals and intensive care units, more people, especially children and older adults, are dying. Moreover, due to the limited number of healthcare professionals, outpatient care, prevention and vaccination aren’t properly covered [11].

Influenza constitutes a recurring threat and therefore requires the continuous allocation of financial resources so that each healthcare system can respond in the best possible way. The economic burden on individuals aged 18-64 due to influenza appears to generate indirect costs of up to 90%. This includes absenteeism from work, caregiving time and reduced productivity due to illness. It may also generate direct costs, which are attributed at an estimated rate of 75% to hospitalizations. Expenses related to influenza increase with age and with the presence of possible underlying health conditions. The cost of hospitalization for high-risk groups is approximately 2.5 times higher compared to the general population [12]. The economic impact of influenza can be observed in other sectors of the social structure, beyond the healthcare system. On average, 2 to 4 workdays may be lost due to influenza, a fact that affects both income and productivity. Even when these workdays are not lost, the quality of work is reduced when it is performed either under illness or under the perception of illness, further decreasing productivity. When that is applied to healthcare personnel, it is expected that the existing health-related consequences become even more significant [13]. Thus, influenza affects economy, the labor market, healthcare systems and the entire structure of community.

As seasonal influenza vaccination is the most effective means of protection available, it is very important to highlight that healthcare professionals play a critical role in the vaccination acceptance of the general population. If the vaccination acceptance among healthcare professionals is low, it is expected that the acceptance in the general population will be also low [5]. Despite the proven contribution of influenza vaccination, coverage remain moderate, even among healthcare professionals. Some of the reasons that may lead healthcare professionals to neither recommend influenza vaccines nor get vaccinated themselves include inadequate access to education regarding the influenza virus and its mechanisms, misconceptions about the benefits and risks of vaccination, the preference for natural immunity, and the absence of underlying chronic health conditions [14]. In contrast, the presence of chronic conditions, the perceived fear of illness and transmission to family members, as well as mandatory vaccination policies, act as reinforcing factors among healthcare professionals. Primary healthcare and educational campaigns can also aid vaccination coverage within the population of healthcare professionals [15].

For this reason, as shown in literature, beliefs, attitudes and behaviors of health professionals depend on various factors and are shaped according to specific conditions. It is important to make efforts to identify factors that influence them, with the aim of designing and implementing educational interventions for health professionals. Taking all the above into consideration, the present review aims to highlight the attitudes, beliefs, and behaviors that health professionals currently have towards influenza vaccination. In addition, the review seeks to discuss the differences that exist in attitudes, beliefs, and behaviors across different continents and among different groups of health professionals.

Although a substantial body of systematic and narrative reviews has examined influenza vaccination uptake among healthcare professionals, the available evidence remains fragmented across regions, professional subgroups, and conceptual frameworks. Individual reviews typically focus on specific countries, income settings, or professional categories, limiting the ability to derive a coherent global interpretation of beliefs, attitudes, and behaviors. Moreover, the relative contribution of behavioral determinants versus structural and policy-related factors remains inconsistently reported across reviews. To address these gaps, the present umbrella review synthesizes evidence from existing reviews to provide a comprehensive, global-level overview of healthcare professionals’ beliefs, attitudes, and behaviors regarding seasonal influenza vaccination. By integrating findings across regions, professional groups, and methodological approaches, this review aims to identify consistent patterns, highlight contextual differences, and delineate evidence gaps relevant to infection prevention strategies and vaccination policy design.

2. Materials and Methods

This umbrella review follows the PRISMA 2020 statement. A literature search was conducted in three databases: PubMed, Cochrane Library, and Google Scholar. The search was performed in December 2025 using specific keywords combined with Boolean operators and asterisks, to ensure comprehensive retrieval of relevant studies. The search query used is the following: (belief* OR attitud* OR behav*) AND (“influenza vaccin*” OR “flu vaccin*”) AND (health OR healthcare OR “health care”).

Based on the search results, articles that met specific criteria were selected to better address the objectives of the present review. These criteria are as follows:

1) Articles must be reviews.

2) Articles must have been published after the following date: 01/01/2000.

3) The language of the full text of articles must be English.

4) Article should focus on a population of healthcare professionals and record the beliefs, attitudes, and behaviors towards influenza vaccination.

Two reviewers independently screened titles, abstracts and full texts for eligibility and extracted data from included reviews. Any disagreements were resolved by consensus.

For Google Scholar, the search was conducted using the same query terms, screening the first 200 results sorted by relevance. Reference lists of eligible reviews were also hand-searched to identify additional relevant studies.

Reviews were selected because they summarize data from original studies and can provide a more comprehensive picture of the situation. The starting date for the search was set as 01/01/2000, as this date allows for a complete and thorough depiction of the situation. Articles with full text available in English were selected because English is the internationally recognized language and is the language required for publication in major scientific journals.

Although the review targeted healthcare professionals, this population is described heterogeneously across the literature using multiple terms (e.g., healthcare workers, HCWs, health workers). To avoid missing eligible reviews due to terminological variability, automated exclusions were minimized and eligibility was confirmed through manual assessment.

Finally, the inclusion of reviews focusing on healthcare professionals and describing their beliefs, attitudes, and behaviors towards influenza vaccination ensured that the articles selected were directly aligned with the aims of this review, thereby enhancing comparability and interpretability of the findings. This approach enables the collection of comparable articles and further facilitates the analysis of the data to be gathered.

To calculate the risk of bias, systematic reviews were assessed for quality using the AMSTAR 2 checklist. The quality assessment was not conducted for reviews as they are considered lower quality than systematic reviews anyway. Narrative (non-systematic) reviews were included for descriptive synthesis only, with the aim of capturing broader thematic patterns across regions and professional groups. The interpretation of key findings and the formulation of overall conclusions were primarily based on evidence derived from systematic reviews and meta-analyses.

3. Results

3.1. Selection and Characteristics of Included Studies

Following the PRISMA guidelines, a total of 950 records were initially identified (Figure 1). After removal of duplicates and initial screening of abstracts, 55 studies remained for further assessment. Following full-text screening, 25 studies fulfilling the selection criteria were finally included in this review. A substantial proportion of records were excluded at the full-text stage after verification that the target population did not meet the predefined inclusion criteria. The high number of exclusions observed during the PRISMA flow diagram reflects the methodological decision to apply a sensitive search strategy.

Regarding risk of bias, out of the 12 systematic reviews assessed for quality using the AMSTAR 2 checklist, 1 was ranked as high quality, 4 as moderate quality, 5 as low quality and 2 as very low quality. The 13 reviews were considered by default of lower quality than systematic reviews.

In the following pages, a detailed table with the characteristics of the 25 studies included in this review, is presented (Table 1). Authors, publication date, region, health profession, aim, materials and methods and beliefs, attitudes and behaviors regarding seasonal influenza vaccination were collected for each study and are presented in Table 1.

3.2. Materials and Methods Used for Data Collection in Included Studies

In this paragraph, a record of the methodological tools, the main design elements, and the theoretical models employed by the 25 studies included in the present review is listed to have a better understanding of the design each study followed. Twelve of the 25 studies included are systematic reviews (Figure 2). In complete accordance, all twelve systematic reviews followed the guidelines of the PRISMA 2020 statement. Most studies conducted structured searches in major scientific databases, with MEDLINE being the most frequently used source. More specifically, 20 studies retrieved data from this database. Only two studies incorporated in their search sources that are part of the so-called ‘grey literature’ [26,34]. All studies attempted to document the beliefs, attitudes, and behaviors of healthcare professionals, as well as the factors that shape these. However, only two studies relied on a specific belief model to achieve this aim (17,37). The model employed by both is the Health Belief Model.

3.3. Knowledge, Attitudes, Beliefs and Behaviors of Healthcare Professionals Around the World

The percentage of healthcare professionals across all continents who accept influenza vaccination shows marked variation (Figure 3). Across the included reviews, reported uptake ranges from approximately 2-44% in several settings without mandates, with pooled estimates around 40% globally, while coverage can exceed 90% where mandatory policies are implemented [25,31,39]. The vaccination behavior of healthcare professionals appears to influence their recommendations, as it is observed that their advice regarding vaccination of the general population often aligns with whether they themselves accept influenza vaccination or not. Regardless of what the exact vaccination coverage rates are, in all continents these rates are significantly lower than the recommended, desirable levels.

Regarding the beliefs and attitudes of healthcare professionals, it appears that they influence the formation of both the intention to vaccinate and the final vaccination behavior. The strength of this influence seems to be greater in developed countries and weaker in developing countries due to the lack of access to healthcare services in developing countries. Beliefs about protecting oneself and one’s family from the influenza virus were the most reported factors positively influencing vaccine acceptance (Table 2). Additionally, attitudes supporting the effectiveness of the vaccine in preventing influenza transmission were also factors leading to acceptance. The two main barriers leading to non-acceptance were perceptions that influenza vaccines cause adverse side effects, making them unsafe, and beliefs that influenza vaccines are ineffective and unnecessary (Table 2).

3.4. Differences Identified Among Healthcare Professionals

The “intention to” vaccinate and influenza vaccination coverage appear to be higher among healthcare professionals working in clinical practice compared to those performing non-clinical roles (Figure 3). Apart from general practitioners, healthcare professionals working in primary healthcare settings have lower vaccination intention and coverage than the expected. Regarding the age and experience of healthcare professionals, it seems that younger professionals with fewer years of work experience demonstrated a higher likelihood of intending to be vaccinated and, ultimately, to get vaccinated, as well as to recommend vaccination to their patients, compared to those of more advanced age and greater work experienced. Medical professionals have higher vaccination intention, vaccination coverage, and frequency of recommending vaccines to patients, compared to other healthcare professionals. Lastly, among medical specialists, the highest levels of vaccination intention and behavior are observed in pediatricians and general practitioners.

Figure 4. Vaccine acceptance in healthcare professionals in clinical practice and non-clinical roles.

Figure 4. Vaccine acceptance in healthcare professionals in clinical practice and non-clinical roles.

4. Discussion

This umbrella review attempted to capture the prevailing situation regarding the knowledge, beliefs, attitudes, and behaviors of professionals in health care concerning the acceptance or refusal of the influenza vaccination. Through the review, a limited availability of data was observed from many low- or middle-income countries in the continents of South America and Africa, as well as some low- or middle-income countries in Asia. This is also evident in other research efforts in the available literature and may be due to insufficient record-keeping observed in most countries of these continents, and the limited resources for the epidemiological investigation of influenza, because these resources are allocated to other, more significant and life-threatening health issues that exist in each respective region [41,42].

Regarding the vaccination behavior of healthcare professionals, the highest vaccination coverage is observed in North America. This finding is also consistent with other studies [43,44]. One of the key factors contributing to higher vaccination coverage in this region is the implementation of mandatory vaccination policies for healthcare professionals in several U.S. states and in Canada. This measure raises issues, such as the resurgence of anti-vaccination movements, the emergence of ethical dilemmas related to the right to freely choose whether to undergo a medical intervention, and the spread of conspiracy theories, yet it is undoubtedly one of the key factors that maintains influenza vaccination coverage among healthcare professionals at high levels [39,45]. Policy and implementation considerations are summarized in Section 4.1.

In contrast, the lowest influenza vaccination coverage among healthcare professionals is observed primarily in African countries and, subsequently, in South American countries, as is also shown by other researchers [46,47,48]. These countries are, mostly, low- or middle-income countries. The availability of resources to meet health needs is limited and primary healthcare services are underdeveloped. Moreover, limited healthcare workforce and urgent health needs essential for survival, leads to substantial gaps in the recording of influenza cases and vaccinations, as well as significant difficulties regarding the cost coverage of vaccines, their availability, and access. As a result, the epidemiological data available for these regions are limited. Though, low vaccination coverage is recorded, which further complicates the public health situation in these areas [49,50,51].

Influenza vaccination coverage among healthcare professionals in Europe and Oceania is similar. Lower than North America’s, but comparatively higher than Africa’s and South America’s [52,53,54,55]. In Europe, as in Oceania, there are no laws mandating influenza vaccination. For this reason, the guidelines concerning the desired vaccination levels for healthcare professionals serve as recommendations rather than obligations. This provides flexibility and freedom of choice; however, it comes at a cost in terms of achieving high levels of vaccination coverage [56,57,58].

Regarding Asia, influenza vaccination coverage among healthcare professionals shows the greatest variability, as it consists of both low- or middle-income and high-income countries [56,59]. Vaccination coverage is higher than South America’s but lower compared to Oceania’s and Europe’s. The Middle East region has the higher vaccination coverage when compared to other countries of Asia. This finding is also reflected in other research efforts [60,61,62].

Overall, the vaccination behavior of healthcare professionals for influenza is considerably lower than the recommended. This is true in all regions. In areas where income is lower, vaccination behavior is even more limited [63,64]. It seems that socioeconomic conditions are important in covering health needs. The inability to cover the cost of healthcare services and the deficiencies in primary healthcare limit access to primary healthcare services. Instead, the emphasis is placed on urgent issues necessary for human survival. As a result, priorities are shaped in such a way that certain public health needs—such as influenza vaccination—are overlooked, even among healthcare professionals [65,66,67,68].

Several studies attempt to document knowledge, beliefs, and attitudes to approach the factors shaping behavior [69,70,71]. In low- or middle-income regions, a divergence is observed between attitudes, beliefs and actual behavior, reducing their usefulness in both predicting and shaping behavior [69,72]. Limited vaccine availability, cost, and lack of access may all contribute to low vaccination coverage. For this reason, although knowledge, attitudes, beliefs, and intention to vaccinate support vaccination behavior, the functional barriers mentioned earlier are responsible for preventing attitudes and beliefs from being reflected in behavior as well as in recommendations to the general population [69,73,74].

Regarding the beliefs and attitudes most frequently have a positive impact on the acceptance of influenza vaccination, healthcare professionals report that they get vaccinated and recommend vaccination against influenza because they believe it enhances protection for themselves and their families [64,75]. They also report the belief that vaccines are an effective method for preventing influenza and infections in general [76,77]. Overall, a sense of immediate risk to oneself and to close family members leads to quicker compliance with the guidelines [75]. Moreover, confidence in vaccine effectiveness is strongly associated with both personal uptake and the likelihood of recommending vaccination to patients. [77].

As for the attitudes and beliefs that act as barriers and lead healthcare professionals to refuse influenza vaccination, the perception of risk prevents individuals from undergoing that intervention, regardless of their level of knowledge about its mechanisms of action [78,79]. Another barrier often mentioned is the belief that influenza vaccines are ineffective in preventing the transmission of the influenza virus, and therefore, do not need to be administered. In contrast to beliefs and attitudes supporting effectiveness, when an intervention is perceived as ineffective, the following question naturally arises: “Why should I undergo or recommend this intervention?” Consequently, healthcare professionals who do not consider influenza vaccines effective do not believe it is necessary to receive or recommend them [80,81].

With regard to the differences observed among various healthcare professionals, those who are actively engaged in clinical practice and come into daily contact with patients tend to think more about protecting themselves and their patients [82]. In contrast, healthcare professionals in administrative roles have much less frequent contact with patients. For this reason, having a reduced exposure with patients, it is reasonable that they exhibit comparatively lower vaccination intention and behavior [83].

Regarding the different specialties among primary healthcare professionals, it was observed that vaccine acceptance is higher among medical professionals compared with other health professionals. One explanation is the variation in knowledge between physicians and nurses or other professionals concerning the mechanisms of action of influenza vaccines [84]. Physicians, having received the most specialized training among healthcare professionals, are better able to understand how influenza vaccines work, the process of immunization, the duration of protection, and the need for booster doses. As a result, they are more likely to accept, receive, and recommend influenza vaccination [85].

Another factor contributing to higher vaccination intention and coverage among healthcare physicians is their role as examples of healthy and protective behaviors in the eyes of the public. General population relies on physicians when making health-related decisions [86]. Physicians can influence healthcare users through their own behavior. For this reason, by considering both physicians’ specialized knowledge about influenza vaccines and their responsibility as healthcare role models, the comparatively higher rates of vaccination intention, coverage, and recommendation observed among physicians can be explained [87,88,89]. The highest rates of vaccination coverage and frequency of vaccine recommendation are observed in the specialties of pediatrics and general medicine [82,90].

• Communication and role modelling: Vaccinated healthcare professionals are more likely to recommend vaccination to patients, reinforcing their role as trusted role models and amplifying impact at the population level [26,29,38].
• Targeted education: Interventions addressing misconceptions about safety and effectiveness can increase uptake, particularly among nurses and non-physician staff, where acceptance is typically lower than physicians by ~10-30 percentage points [18,77,82].
• Convenient access: On-site and free-of-charge vaccination within healthcare facilities improves uptake, especially in primary care and outpatient settings with lower baseline coverage [35,52].
• Mandates and governance: Mandatory vaccination policies are consistently associated with the highest coverage, often exceeding 90%, compared with voluntary programs where coverage commonly remains below 60% [39,44,45].

The findings of this umbrella review support several actionable strategies to increase influenza vaccination coverage among healthcare professionals and strengthen downstream effects on patient uptake.

4.1. Implications for Public Health Policy and Practice

Key strengths of this umbrella review include the comprehensive literature search, the inclusion of high-level evidence from systematic reviews and meta-analyses, and the global synthesis of behavioral determinants across regions and professional groups.

A further methodological consideration relates to potential overlap of primary studies across the included reviews. A formal overlap assessment was not conducted; therefore, some degree of double-counting of primary studies cannot be excluded.

It should be noted that the present review was conducted under the influence of certain key limitations. A significant limitation of this review is the methodological variations in the sample of studies that were included. The sample consists of both systematic and non-systematic reviews. The strict and restrictive nature of systematic reviews, the application of specific eligibility criteria, and the use of internationally accepted guideline tools for their implementation contribute to identifying the most relevant and robust evidence. All the above, place the design of systematic reviews at the top of the evidence hierarchy for review articles. However, in our study most of the systematic reviews included were classified as of moderate or low quality. Simple literature reviews may be conducted under the influence of certain criteria, but they are more inclusive and aim to outline a very broad framework of the subject of study. Taking all the above into account, the strength of the evidence was probably affected.

Remaining on the topic of the methodological design of the studies, another limitation arises from the heterogeneity of the studies included in the reviews examined by the present umbrella review. Different research designs offer different levels of strength to the findings they report. As a result, when a review includes all types of research designs without restrictions, some of the findings may become weaker. The present review examined reviews that contain all types of primary research designs. For this reason, it is also impacted in terms of the strength of certain findings.

The final major limitation identified relates to the variation and inconsistency in how beliefs, attitudes, and intention towards influenza vaccination are recorded and assessed. Vaccination behavior is reflected through vaccination coverage and the recommendations made by health professionals. However, knowledge, beliefs, attitudes, and intention are factors that depend on many variables. This makes their estimation and description difficult. The studies included in the reviews examined by this review approached the recording and determination of these elements in different ways. As a result, a “blend” of data is produced, collected and analyzed in various and heterogeneous ways. Due to the differences in data collection and analysis procedures, it becomes more difficult to compare these data. When the ability to make comparisons is limited because of data heterogeneity, the results that emerge are weakened.

The present umbrella review identified certain gaps, with the aim of being taken into consideration in future research efforts, so that the approach and the overall understanding of primary healthcare professionals’ beliefs, attitudes, and behaviors regarding influenza vaccination can be continuously improved.

The main gap identified is the significant absence of data from low- and middle-income regions, highlighting the need for increased research activity in these settings to support more reliable and comprehensive conclusions.

Finally, a key point that is not described in the literature is the focus of research efforts in relation to the differences within the population of primary healthcare professionals. Most studies examine health professionals in general as the reference population. However, under the “umbrella” of health professionals, there are many distinct subgroups, such as physicians, nurses, community health workers and pharmacists. It is undeniable that developing research efforts that study and record the attitudes and beliefs of each specific subgroup within the broader health professional population would greatly facilitate the drawing of clearer conclusions.

5. Conclusions

Considering all the data presented in this umbrella review, influenza vaccination behavior of health professionals in different regions of the world is considerably lower than the recommended levels. North America has the highest levels of vaccination coverage probably due to mandatory influenza vaccination policies. The weakest vaccination behavior is found in African countries. Overall, low- and middle-income countries show significantly lower vaccination behavior compared with high-income countries. Insufficient resources for meeting basic health needs, combined with limited access to influenza vaccines, contribute to the low vaccination coverage. Regarding the differences among healthcare professionals, those in clinical practice, within hospital settings, and younger with less work experience show higher levels of intention to vaccinate, vaccination coverage, and encouragement of patients to get vaccinated. Pediatricians and general practitioners receive the influenza vaccine more frequently. Apart from general practitioners and pediatricians, other primary healthcare professionals show insufficient vaccination levels.

Acceptance can be influenced by knowledge, attitudes and beliefs. Protection that vaccines offer to healthcare professionals, and their families strongly impacts vaccine acceptance. In contrast, beliefs concerning adverse effects and vaccine safety act as barriers to vaccine uptake and recommendation. The recommendations that health professionals give are influenced by whether they accept influenza vaccines themselves. The general population is influenced by healthcare professionals, due to the more frequent contact and trust-based relationship that develops between them. Healthcare professionals are viewed as role models for health-related topics. For this reason, enhancing influenza vaccination uptake among healthcare professionals could substantially strengthen public confidence and improve vaccination behavior in the wider community.