Influenza Vaccination Decision Research Articles

A Cross-Sectional Factor Analysis of COVID-19 and Influenza Vaccination Decisions in a Racially Diverse Western Pennsylvania Community.

Influenza and COVID-19 vaccination rates remain suboptimal, demanding new community-centric approaches that improve targeted counseling and increase vaccine uptake. Notably, racially diverse communities show high vaccine hesitancy, yet most existing vaccine studies focus on white, college-educated cohorts. Here, we identify factors influencing vaccination decisions of patients at Turtle Creek Primary Care clinic in Turtle Creek, PA, a racially-diverse borough. A retrospective mixed-methods study of the predominantly non-white patient population at Turtle Creek Primary Care clinic, a clinic caring for >70% minority patients. Fourteen factors emerged that patients reported were crucial to vaccine decision-making. Of these factors, top reasons for COVID-19 vaccine hesitancy were trust in vaccines, vaccine side effects, perceived vaccine knowledge, and faith/religion. Top reasons for influenza vaccine hesitancy were perceived need, vaccine side effects, trust in vaccines, and habitual behaviors. We also uncovered correlations between vaccine decision factors and sociodemographic factors. Participants > 65-years-old were more likely to cite personal safety in choosing to get the COVID-19 vaccine, while non-white participants were more likely to cite others' safety. Participants > 65-years-old were also more likely to cite personal safety in influenza vaccine decision-making, and non-female participants were more likely to cite perceived need for influenza vaccines. These data uncover targetable factors contributing to vaccine hesitancy and aid in developing community-centered, personalized vaccine education approaches in Turtle Creek and analogous minority communities.

Social and demographic patterns of influenza vaccination coverage in Norway, influenza seasons 2014/15 to 2020/21.

To examine influenza vaccination coverage among risk groups (RG) and health care workers (HCW), and study social and demographic patterns of vaccination coverage over time. Vaccination coverage was estimated by self-report in a nationally representative telephone survey among 14919 individuals aged 18-79years over seven influenza seasons from 2014/15 to 2020/21. We explored whether belonging to an influenza RG (being >=65years of age and/or having >=1 medical risk factor), being a HCW or educational attainment was associated with vaccination status using logistic regression. Vaccination coverage increased from 27% to 66% among individuals 65-79years, from 13% to 33% among individuals 18-64years with >=1 risk factor, and from 9% to 51% among HCWs during the study period. Being older, having a risk factor or being a HCW were significantly associated with higher coverage in all multivariable logistic regression analyses. Higher education was also consistently associated with higher coverage, but the difference did not reach significance in all influenza seasons. Educational attainment was not significantly associated with coverage while coverage was at its lowest (2014/15-2017/18), but as coverage increased, so did the differences. Individuals with intermediate or lower education were less likely to report vaccination than those with higher education in season 2018/19, OR=0.61 (95% CI 0.46-0.80) and OR=0.58 (95% CI 0.41-0.83), respectively, and in season 2019/20, OR=0.69 (95% CI 0.55-0.88) and OR=0.71 (95% CI 0.53-0.95), respectively. When the vaccine was funded in the COVID-19 pandemic winter of 2020/21, educational differences diminished again and were no longer significant. We observed widening educational differences in influenza vaccination coverage as coverage increased from 2014/15 to 2019/20. When influenza vaccination was funded in 2020/21, differences in coverage by educational attainment diminished. These findings indicate that economic barriers influence influenza vaccination decisions among risk groups in Norway.

Healthcare professional and professional stakeholders’ perspectives on vaccine mandates in Switzerland: A mixed-methods study

BackgroundThere currently are no mandatory vaccines in Switzerland. However, Swiss federal legislation allows for vaccination mandates in settings where the risk of transmission to vulnerable groups is high, such as healthcare professionals (HCPs) working with vulnerable patients. Since HCPs are trusted information sources, a priority population for COVID-19 vaccination, and potentially subjected to mandates, we investigated HCP perspectives on mandates. MethodsA national online survey was administered to HCPs (October 2020-March 2021), including vaccine mandates questions concerning patients (measles) and HCPs (influenza). We qualitatively investigated HCP mandate perspectives through: (1) 34 interviews with HCPs, HCP professional society representatives, and health authorities; (2) a focus group discussion (FGD) with complementary medicine (CM) and biomedical physicians, and Swiss Federal Vaccination Commission members. Results1933 participants (496 physicians, 226 pharmacists, 607 nurses, 604 midwives) responded to the survey. Quantitative results show all professional groups preferred shared parent-HCP measles vaccine decisions (65%, 54%, 50%, 48%, respectively; p for trend < 0.001). Midwives (87%) and nurses (70%) preferred individual influenza vaccination decisions for HCPs, while physicians (49%) and pharmacists (44%) preferred shared employee-employer decisions (p for trend < 0.001). Physicians (p < .001) and pharmacists (p < .01) with CM training favored individual influenza vaccination decisions. Qualitative results show general HCP opposition to vaccine mandates, mainly because participants argued how other approaches, such as HCP training and better information, could encourage uptake. Arguments against COVID-19 mandates included insufficiently documented long-term safety/efficacy data. From participants’ perspectives, mandated vaccination should be used as a last resort. Some participants expressed fear that with mandates, notably for influenza and COVID-19, some HCPs might leave their jobs. HCPs were unsure what vaccine mandates would concretely look like in practice, particularly regarding sanctions for non-compliance and enforcement. ConclusionIn Switzerland, HCPs generally were opposed to vaccination mandates. Clarity and guidance are needed from health authorities to better inform discussions around vaccine mandates.

Personal and social patterns predict influenza vaccination decision

BackgroundSeasonal influenza vaccination coverage remains suboptimal in most developed countries, despite longstanding recommendations of public health organizations. The individual’s decision regarding vaccination is located at the core of non-adherence. We analyzed large-scale data to identify personal and social behavioral patterns for influenza vaccination uptake, and develop a model to predict vaccination decision of individuals in an upcoming influenza season.MethodsWe analyzed primary data from the electronic medical records of a retrospective cohort of 250,000 individuals between the years 2007 and 2017, collected from 137 clinics. Individuals were randomly sampled from the database of Maccabi Healthcare Services. Maccabi’s clients are representative of the Israeli population, reflect all demographic, ethnic, and socioeconomic groups and levels. We used several machine-learning models to predict whether a patient would get vaccinated in the future. Models’ performance was evaluated based on the area under the ROC curve.ResultsThe vaccination decision of an individual can be explained in two dimensions, Personal and social. The personal dimension is strongly shaped by a “default” behavior, such as vaccination timing in previous seasons and general health consumption, but can also be affected by temporal factors such as respiratory illness in the prior year.In the social dimension, a patient is more likely to become vaccinated in a given season if at least one member of his family also became vaccinated in the same season. Vaccination uptake was highly assertive with age, socioeconomic score, and geographic location. An XGBoost-based predictive model achieved an ROC-AUC score of 0.91 with accuracy and recall rates of 90% on the test set. Prediction relied mainly on the patient’s individual and household vaccination status in the past, age, number of encounters with the healthcare system, number of prescribed medications, and indicators of chronic illnesses.ConclusionsOur ability to make an excellent prediction of the patient’s decision sets a major step toward personalized influenza vaccination campaigns, and will help shape the next generation of targeted vaccination efforts.

"Flu-Floppers": Factors Influencing Families' Fickle Flu Vaccination Patterns.

While influenza vaccination in the prior year is a strong predictor of subsequent vaccination, many families do not have static vaccination patterns. This study examined factors guiding influenza vaccination decisions among parents whose children sporadically received the influenza vaccination (flu-floppers). We administered surveys to 141 flu-flopper families. Surveys included 21 factors associated with vaccine decision making. A conceptual framework of "passive" and "active" decision making was used to assess parental motivators behind vaccine decisions. The most common reason for vaccinating was a desire to prevent influenza (45%). The most common reason for not vaccinating was a belief that influenza vaccination is not effective (29%). Most parents (88%) reported an active reason in years when their child was vaccinated, while only 43% reported an active reason when their child was not vaccinated (P < .00001). These findings may guide efforts to increase influenza vaccination rates in children most amenable to vaccination.

Managing Influenza Vaccination: The Role of Bounded Rationality

Problem Definition: Under the assumption of full rationality, the existing literature shows that self-interested individuals ignore the social benefit of protecting others when making influenza vaccination decisions (positive externality), which results in social welfare loss. In this paper, we study the impact of individual bounded rationality in influenza vaccination settings. Academic/Practical Relevance: We examine the commonly used vaccination policies in practice such as subsidization and taxation and provide managerial guidelines for a social planner. Methodology: We develop a simple game-theoretic model, in which individuals boundedly rationally estimate the vaccinated fraction of the population through anecdotal reasoning. We characterize individuals' optimal vaccination decisions and the social planner's optimal subsidization and taxation policies. Results: We find that individual bounded rationality may lead to a positive externality improving social welfare. When the zero-risk vaccination fraction is low and the vaccination cost is at a particular level, the negative effect of self-interested individuals' vaccination decisions could be completely eliminated because of bounded rationality and thus the socially optimal welfare is achieved. In sharp contrast to the setting of full rationality, we show that the optimal social welfare may never be achieved by any subsidization or taxation policy under individual bounded rationality. Managerial Implications: We demonstrate the welfare loss by ignoring individual bounded rationality when implementing a vaccination policy. The social planner should consider the level of individual bounded rationality when using subsidization or taxation in practice. We find that the social planner should induce a particular level of accuracy in estimating the vaccinated fraction for the individuals when the vaccination cost is sufficiently low to achieve the socially optimal welfare by subsidization or taxation; otherwise, inducing individuals to obtain more accurate estimation of the vaccinated fraction is always recommended.

Social Influences on Influenza Vaccination Decision Among Senior Citizens in Taiwan, South Korea, and Switzerland

Background: Although the vaccination against influenza has been found to be an impactful and cost-effective protection against the disease, coverage is incomplete. This draws attention to the factors of people’s flu vaccination decisions. The article contributes to understanding the effect of social factors on vaccination behavior. Social factors comprise the ways people may be affected by their peers and the mass media or by healthcare providers and health institutions. Method: Samples of some 200 senior citizens were interviewed by write-in questionnaire in Taiwan, South Korea and the Swiss canton Ticino. Results: Encouragement by the family physician and a combination of the frequency of contact with vaccination subjects in interpersonal and traditional mass communication and perceived concern with vaccination there increased vaccination rates in the two Asian countries, and model behavior and experience strongly affected vaccination in South Korea, all in bivariate analyses. Multivariate regression in Taiwan and Korea loses the impact of mass media. Perceived concern in sources showed complete mediation by frequency of interpersonal communication in Taiwan and partial mediation in Korea. Conclusion: There is indeed a relationship between social factors and individual vaccination behavior, which, however, is far from being pervasive. There’s hardly any result with direct relevance for the hypotheses that shows up in all three countries, and a meaningful and clear pattern in the differences between the Swiss sample on the one hand and the two Asian countries emerges.

Factors affecting influenza vaccination decisions in patients with cardiovascular diseases – selected aspects of research

Factors affecting influenza vaccination decisions in patients with cardiovascular diseases – selected aspects of research

Socialization, Indifference, and Convenience: Exploring the Uptake of Influenza Vaccine Among Medical Students and Early Career Doctors.

The Chief Medical Officer recommends that all health care workers receive an influenza vaccination annually. High vaccination coverage is believed to be the best protection against the spread of influenza within a hospital, although uptake by health care workers remains low. We conducted semistructured interviews with seven medical students and nine early career doctors, to explore the factors informing their influenza vaccination decision making. Data collection and analysis took place iteratively, until theoretical saturation was achieved, and a thematic analysis was performed. Socialization was important although its effects were attenuated by participants’ previous experiences and a lack of clarity around the risks and benefits of vaccination. Many participants did not have strong intentions regarding vaccination. There was considerable disparity between an individual’s opinion of the vaccine, their intentions, and their vaccination status. The indifference demonstrated here suggests few are strongly opposed to the vaccination—there is potential to increase vaccination coverage.

Learning to Trust Flu Shots: Quasi-Experimental Evidence from the 2009 Swine Flu Pandemic.

This paper studies consumer learning in influenza vaccination decisions. We examine consumer learning in influenza vaccine demand within a reduced form instrumental variable framework that exploits differences in risk characteristics of different influenza viruses as a natural experiment to distinguish the effects of learning based on previous influenza vaccination experiences from unobserved heterogeneity. The emergence of a new virus strain (influenza A H1N1/09) during the 2009 'Swine flu' pandemic resulted in two different vaccines being recommended for distinct population subgroups with some people, who were not usually targeted by seasonal vaccination programs, being specifically recommended for the new Swine flu vaccine. We use these differences in vaccination targeting to construct instrumental variables for estimating the effect of past influenza vaccination experiences on the demand for pandemic vaccine. We find large causal effects of previous seasonal vaccination on pandemic vaccination. Causal effects of past influenza vaccination experiences on perceived vaccination safety are likely to be an important pathway linking past vaccination experiences with future vaccine uptake. Our results suggest a significant role of learning in vaccination decisions. Current efforts to expand seasonal vaccination may thus have potentially important long-term effects on future influenza vaccination levels and pandemic preparedness. Copyright © 2016 John Wiley & Sons, Ltd.

Seasonal Influenza Vaccination amongst Medical Students: A Social Network Analysis Based on a Cross-Sectional Study.

IntroductionThe Chief Medical Officer for England recommends that healthcare workers have a seasonal influenza vaccination in an attempt to protect both patients and NHS staff. Despite this, many healthcare workers do not have a seasonal influenza vaccination. Social network analysis is a well-established research approach that looks at individuals in the context of their social connections. We examine the effects of social networks on influenza vaccination decision and disease dynamics.MethodsWe used a social network analysis approach to look at vaccination distribution within the network of the Lancaster Medical School students and combined these data with the students’ beliefs about vaccination behaviours. We then developed a model which simulated influenza outbreaks to study the effects of preferentially vaccinating individuals within this network.ResultsOf the 253 eligible students, 217 (86%) provided relational data, and 65% of responders had received a seasonal influenza vaccination. Students who were vaccinated were more likely to think other medical students were vaccinated. However, there was no clustering of vaccinated individuals within the medical student social network. The influenza simulation model demonstrated that vaccination of well-connected individuals may have a disproportional effect on disease dynamics.ConclusionsThis medical student population exhibited vaccination coverage levels similar to those seen in other healthcare groups but below recommendations. However, in this population, a lack of vaccination clustering might provide natural protection from influenza outbreaks. An individual student’s perception of the vaccination coverage amongst their peers appears to correlate with their own decision to vaccinate, but the directionality of this relationship is not clear. When looking at the spread of disease within a population it is important to include social structures alongside vaccination data. Social networks influence disease epidemiology and vaccination campaigns designed with information from social networks could be a future target for policy makers.

Predictors of IV behaviors during and after the 2009 influenza pandemic in France

BackgroundControversies about the 2009 H1N1 pandemic influenza vaccination might have impacted the motivational processes that underlie individual immunization against seasonal influenza. The purpose of this article is to investigate correlates of vaccine uptake during and after the pandemic. MethodsData from the 1174 subjects of the CoPanFlu France cohort aged 15 and over were used. We used logistic regression models to identify social and behavioral predictors of getting vaccinated against seasonal influenza in 2009–2010 and in 2010–2011 and against H1N1 influenza in 2009–2010. ResultsThis study points out that correlates of vaccination behaviors varied according to the vaccine. Respondents under 65 years who adopted the seasonal influenza vaccine were, as usual, more likely to belong to a target group and have a lower education, contrary to subjects who chose the pandemic vaccine. Exceptionally during the pandemic, a higher socioeconomic status also led to adoption of either vaccine. Motivational processes differed by vaccine. Uptaking the “new” pandemic vaccine was the result of a deliberative decision-making process, influenced by cognitive factors related to the pandemic context (such as perceived severity of the H1N1 flu strain and trust in public health authorities). In contrast, respondents got the seasonal flu vaccine without relying on explicit justifications, but instead through habit of performing this behavior in the past. ConclusionsTarget groups for seasonal influenza but not those for pandemic influenza were more likely to adopt the pandemic vaccine, which is a cause for great concern. This may be due to large extent to the automatic and habitual nature of influenza vaccination decisions. Public health authorities, should pay more attention to situational than informational cues to facilitate vaccine uptake among priority groups, especially in case of mild pandemic influenza.

Management Insights

Management Insights

A Game-Theoretic Model of International Influenza Vaccination Coordination

Influenza vaccination decisions in one country can influence the size of an outbreak in other countries due to interdependent risks from infectious disease transmission. This paper examines the inefficiency in the allocation of influenza vaccines that is due to interdependent risk of infection across borders and proposes a contractual mechanism to reduce such inefficiencies. The proposed contract is based on an epidemic model that accounts for intranational transmission and that from a source country where the dominant strain emerges. The contract reduces the overall financial burden of infection globally and improves the total number infected by seasonal influenza outbreaks. This is consistent with recent recommendations to improve pandemic preparedness. Numerical experiments demonstrate that the benefits of the contract can prevent millions of influenza cases and save tens of millions of dollars, and that the benefits are even greater when cross-border transmission is higher, even if cross-border transmission parameters have moderate estimation errors. This paper was accepted by Martin Lariviere, operations management.

Factors Associated with Influenza Vaccination Decisions among Patients with Mental Illness

To determine influenza (flu) vaccination status among the mentally ill population and identify factors associated with vaccination status. A non-interventional, cross-sectional study was conducted. A self-administered survey to investigate the vaccination status and perceptions related to flu vaccine was administered between October 2011-January 2012 in an outpatient psychiatry clinic that served the indigent, severely mentally ill population of Alabama. All statistical analyses were based upon a significance level of 0.05. Of the 736 patients invited, 302 participated (41%). Only 28.4% were vaccinated in 2010-2011 and 24.2% had been vaccinated at the time of the survey for 2011-2012. Respondents who had private health insurance, received a recommendation from healthcare providers, and who perceived a greater degree of vaccine effectiveness were more likely to obtain flu vaccination while respondents who had education beyond high school and were more in agreement that they can get the flu from the vaccine were less likely to obtain flu vaccination. All of the above factors accounted for 26.7% of vaccination decisions. The flu vaccination rate among this study's population was lower than the general population. Interventions targeting the above factors should help increase vaccination rates among the mentally ill population.

Conscious Consideration of Herd Immunity in Influenza Vaccination Decisions

Influenza vaccination decisions may be influenced by perceived risk reduction related to herd immunity. This paper examines how free-riding (i.e., foregoing vaccination because of reduced risk perceptions related to herd immunity) or protective benefits to the community affect vaccination decisions. A survey of a nationally representative panel of U.S. adults (N=442 respondents; data collected and analyzed during 2012) asked about how respondents made vaccination decisions, including whether and how vaccination among the members of respondents' social networks influenced their own vaccination decisions. Most individuals (61%) reported that vaccination in the social network would not influence their decision. Among those perceiving being influenced by vaccination in their social network, most stated that an increase in network vaccination coverage would make them more likely to get vaccinated, rather than less. Overall, only 6% (28 of 442) gave a response consistent with the reduced-risk logic of herd immunity, which was more common among those stating that they would be less likely to get vaccinated (emphasizing free-riding) than among those more likely to get vaccinated (emphasizing social protection; 33% vs 11%, two-sided, p=0.0005). The reduced-risk logic of herd immunity, and more specifically free-riding, is consciously considered by relatively few individuals. Far more common are social influences bolstering personal vaccination, such as peer pressure and social learning (6% vs 11%, two-sided, p=0.015). Interventionists may be more successful by capitalizing on existing social-influence considerations than by trying to combat the conscious lure of free-riding.

The influence of altruism on influenza vaccination decisions

Game theory is based on the assumption that individuals act according to self-interest and make decisions that maximize their personal payoffs. To test this fundamental assumption, we conducted a survey study in the context of influenza vaccination decisions. Contrary to the assumption of self-interest, we found that altruism plays an important role in vaccination decisions. Nevertheless, altruistic motivation has not yet been considered in epidemiological models, in predictions of vaccination decisions or in the design of vaccination policies. To determine the impact of altruism on the adherence to optimal vaccination policies and on resulting disease burden, we incorporated altruism into a game-theoretic epidemiological model of influenza vaccination. We found that altruism significantly shifted vaccination decisions away from individual self-interest and towards the community optimum, greatly reducing the total cost, morbidity and mortality for the community. Therefore, promoting altruism could be a potential strategy to improve public health outcomes.

Parental perspectives on influenza vaccination in children with asthma

Influenza is an important cause of epidemic and pandemic disease leading to mortality and morbidity in children. Despite great efforts to increase influenza vaccination, many children with chronic medical conditions do not receive influenza vaccine. Our aim was to identify the demographic factors and asthma-associated characteristics related to vaccination, caregivers' attitudes and knowledge about influenza disease during the 2007-2008 influenza season. Caregivers of children with asthma were surveyed via a self-administered questionnaire to document their knowledge about influenza disease and vaccine and factors influencing vaccination. We enrolled 311 children with asthma. The rate of lifetime influenza vaccination was 69.5%, whereas 51.8% of the patients had been vaccinated in the current season. There were no significant differences in demographic factors and asthma control parameters between the groups who received or did not receive influenza vaccine. Most of the parents whose children were vaccinated believed that influenza vaccination would decrease the prevalence and severity of asthma attacks (P < 0.05). The most important reason cited by parents for deciding on the influenza vaccine for their child was physician recommendation (80.1%). The major reasons for declining the vaccination were unawareness that the influenza vaccine was a requirement for their child (29.3%) and illness at the time of vaccination (20%). Physician recommendation is important in the influenza vaccination decision. Demographic factors and asthma control parameters had no influence on immunization uptake but parental beliefs and attitudes could be determinant. Greater effort is needed to increase influenza vaccination rates, in children with asthma.

Workplace Vaccination and Other Factors Impacting Influenza Vaccination Decision among Employees in Israel

The study examined the factors affecting the decision to be vaccinated against influenza among employees in Israel. The research, conducted in 2007/2008, included 616 employees aged 18−65 at various workplaces in Israel, among them companies that offered their employees influenza vaccination. The research questionnaire included socio-demographic characteristics, and the Health Belief Model principles. The results show that the significant factors affecting vaccination compliance include a vaccination program at workplaces, vaccinations in the past, higher levels of vaccine’s perceived benefits, and lower levels of barriers to getting the vaccine. We conclude that vaccine compliance is larger at companies with workplace vaccination programs providing easier accessibility to vaccination.

Subjective and Objective Risk as Predictors of Influenza Vaccination during the Vaccine Shortage of 2004-2005

We aimed to identify the role of objective risk status and subjective risk beliefs in influenza vaccination decisions during the recent rationing of influenza vaccine. A random sample of 300 Americans, obtained through random-digit dialing, was interviewed regarding influenza vaccination practices and beliefs in September 2004 and again in March 2005. One-half of individuals at high risk of influenza did not know that they were at high risk and, therefore, were not vaccinated. Respondents at high objective risk were more likely to report having been vaccinated than respondents who were not at high objective risk (36% vs. 6%, respectively; odds ratio, 8.31; 95% confidence interval, 3.65-18.88). However, a more powerful predictor of self-reported vaccination was subjective risk (64% vs. 7%, respectively; odds ratio, 24.02; 95% confidence interval, 12.18-48.09). Subjective risk fully mediated the relationship between objective risk and vaccination. Other predictors of vaccination included physician recommendation, habit, prior vaccination intention, belief that the influenza vaccine is safe and effective, perceived likelihood of getting influenza, and trait neuroticism. Health communication efforts must be more effective in persuading adults with chronic illness and individuals in contact with persons at risk that they should be vaccinated against influenza.