Demographic and socioeconomic determinants of influenza vaccination disparities among university students

Food insecurity and COVID-19 vaccine hesitancy among adults in the United States (US)

BACKGROUND

Some documented barriers of vaccination behaviors include social determinants of health (SDoH). While there have been many devastations from COVID-19, food security has fluctuated during the pandemic. The purpose of this study is to examine the association with food insecurity and vaccine hesitancy among adults in the U.S.

METHODS

In response to the COVID-19 pandemic, Federal agencies created the online Household Pulse Survey (HPS) to track social outcomes of the pandemic in the U.S. We performed cross-sectional analysis with data from the HPS collected between March 30, 2022, and April 11, 2022 (Week 44) on adults (N = 6449, weighted N = 37,687,910). Vaccine hesitancy was divided into two groups: 1) probably, not sure, probably not, and definitely not receiving the vaccine, and 2) received the vaccine and definitely will get the vaccine. Food sufficiency was a binary variable (Yes/no) based on the question that best described the food eaten in the household the last 7 days. Chi-square tests and multivariable logistic regressions were conducted using replicate weights with SAS. Logistic regressions adjusted for sex, age, race and ethnicity, income, education, COVID-19 infection, health insurance, food insecurity, children <17 years, remote work, health worker status, functional status, and mental health.

RESULTS

During HPS Week 44, 11.2 % of represented Americans experienced food insecurity and 13.8 % were vaccine hesitant. The unadjusted odds ratio was 2.41 (95 % CI = 1.30, 4.50), suggesting adults with food insecurity were more likely to be vaccine hesitant than those with food security. After adjusting for age, sex, race and ethnicity, marital status, and COVID-19 history, the statistical significance remained (AOR = 2.14, 95 % CI = 1.15, 3.99). However, after adjusting for education, we no longer observed a significant association (AOR = 1.70, 95 % CI = 0.89, 3.34), and it remained insignificant in the fully adjusted model (AOR = 1.62, 95 % CI = 0.78, 3.34).

CONCLUSION

Overall, adults with food insecurity were 2.41 times as likely as those with food security to also have vaccine hesitancy. Education mediated the relationship between food insufficiency and vaccine hesitancy. Programs to improve vaccination rates need to also focus on food sufficiency.

Exploring strategies to increase college students' motivation to receive their annual influenza vaccine

OBJECTIVE

To evaluate college students' awareness of an educational initiative to increase campus influenza vaccination rates and strategies to improve it.

PARTICIPANTS

Students attending a large public comprehensive university.

METHODS

An investigator-developed, online survey evaluated awareness of the initiative, the students' perception of incentives, and other motivations to receive seasonal influenza vaccine.

RESULTS

The vaccination rate was 43%, despite low awareness of the initiative (28%). Awareness was significantly higher among vaccinated students (p = 0.0013). Having knowledge that appointments to receive vaccine were not needed increased the motivation of vaccinated students more than unvaccinated students (p = 0.0001). Personal influencers increased motivation of vaccinated students only when they were aware of the initiative (p = 0.04). Tangible incentives did not motivate students.

CONCLUSIONS

Campus vaccination rates increased despite low initiative awareness. Improvements to the initiative should include strategies to increase emphasis on vaccination program conveniences like accessibility and perhaps engage personal influencers more.

Association of social vulnerability and influenza vaccination rates for Annual Medicare Enrollees at the county-level in the United States

INTRODUCTION

Influenza is a preventable acute respiratory illness with a high potential to cause serious complications and is associated with high mortality and morbidity in the US. We aimed to determine the specific community-level vulnerabilities for different race/ethnic communities that are most predictive of influenza vaccination rates.

METHODS

We conducted a machine learning analysis (XGBoost) to identify community-level social vulnerability features that are predictive of influenza vaccination rates among Medicare enrollees across counties in the US and by race/ethnicity.

RESULTS

Population density per square mile in a county is the most important feature in predicting influenza vaccination in a county, followed by unemployment rates and the percentage of mobile homes. The gain relative importance of these features are 11.6%, 9.2%, and 9%, respectively. Among whites, population density (17% gain relative importance) was followed by the percentage of mobile homes (9%) and per capita income (8.7%). For Black/African Americans, the most important features were population density (12.8%), percentage of minorities in the county (8.0%), per capita income (6.9%), and percent of over-occupied housing units (6.8%). Finally, for Hispanics, the top features were per capita income (8.4%), percentage of mobile homes (8.0%), percentage of non-institutionalized persons with a disability (7.9%), and population density (7.6%).

CONCLUSIONS

Our study may have implications for the success of large vaccination programs in counties with high social vulnerabilities. Further, our findings suggest that policies and interventions seeking to increase rates of vaccination in race/ethnic minority communities may need to be tailored to address their specific socioeconomic vulnerabilities.

Catch the tweet to fight the flu: Using Twitter to promote flu shots on a college campus

Objective: Over the 2018-2019 flu season we conducted a randomized controlled trial examining the efficacy of a Twitter campaign on vaccination rates. Concurrently we investigated potential interactions between digital social network structure and vaccination status. Participants: Undergratuates at a large midwestern public university were randomly assigned to an intervention (n = 353) or control (n = 349) group. Methods: Vaccination data were collected via monthly surveys. Participant Twitter data were collected through the public-facing Twitter API. Intervention impact was assessed with logistic regression. Standard network science tools examined vaccination coverage over online social networks. Results: The campaign had no effect on vaccination outcome. Receiving a flu shot the prior year had a positive impact on participant vaccination. Evidence of an interaction between digital social network structure and vaccination status was detected. Conclusions: Social media campaigns may not be sufficient for increasing vaccination rates. There may be potential for social media campaigns that leverage network structure.

A survey of university students on attitudes, behaviors, and intentions toward influenza vaccination

Objective To determine attitudes, behaviors, and intentions of university students regarding influenza vaccination.ParticipantsUndergraduate, graduate, and professional students enrolled at a private, midwestern university.Methods A 24-item electronic survey was designed and distributed after literature review and inputs from experts on immunizations. Bivariate tests were performed to observe differences between various subgroups of respondents (age, gender, race/ethnicity, housing, and academic program). Multivariate logistic regression was performed to find associations with their vaccination preferences.Results Of 3,267 complete responses (36.3% of total students), 75% reported obtaining influenza vaccination in 2016-2017. Vaccination rates were highest for Asian (81.0%) and lowest for Black students (59.6%). Health professional student vaccination rates of 89.3% were achieved with a vaccination mandate in place. Lowest immunization rates were identified for law (47.1%) and business (52.7%) students. Positive promotional factors were identified.Conclusions Access to free, on-campus vaccinations, mandates and promotional efforts are associated with high influenza vaccination rates.

COVID-19 Vaccination under Conditions of War in Ukraine

The COVID-19 pandemic, which spread around the world in 2020, changed the lives of millions of people and affected the life and functioning of all countries and people without exception. With the emergence of the opportunity to be vaccinated against COVID-19, the problem of making a decision about vaccination also appeared. But it has become increasingly clear that the coronavirus is moving into the group of annual viral epidemic diseases that occur every year in different countries during the seasonal wave of acute respiratory viral infections. The ongoing COVID-19 pandemic against the background of the adoption of serious quarantine measures indicates the need for large-scale vaccination of the population as the most effective way to protect against COVID-19. In this article, we pay special attention to vaccination, as the main factor in ensuring health, reducing the morbidity and severity of the course of the COVID-19 disease, and an important task of the state and modern public administration.

Effects of Vaccine Literacy, Health Beliefs, and Flu Vaccination on Perceived Physical Health Status among Under/Graduate Students

Physicians highlight that receiving the flu vaccine is critical, especially during the COVID-19 pandemic period. Younger groups' flu vaccination coverage is very low, and this tendency is potentially related to a lower level of vaccine literacy and perceptions toward vaccination. This study investigated the relationship between flu vaccine literacy, health beliefs, and flu vaccinations (benefit, barrier, severity, and susceptibility) and their impact on perceived health status controlling for socioeconomic factors. It used the Health Belief Model andHealth Literacy Skills Framework with under/graduate students (N = 382) in Ohio, U.S. Path analyses were performed to examine the causal process using SPSS and Amos 23.0. Indicators of CFI, RMSEA, SRMR, and the chi-square/df of the path models were good-acceptable. Vaccine literacy directly impacted on health beliefs and vaccination. Susceptibility belief directly influenced perceived health status. The mediation effects of health beliefs (benefit, barrier) between vaccine literacy and vaccination were confirmed. The study highlights the need for healthcare providers and governments to work together to improve flu vaccine literacy and reduce negative perceptions toward vaccination among younger populations. Educational programs and official communication channels can be used to address concerns and provide accurate information about vaccines to increase flu vaccination rates and protect public health.

Current aspects of vaccination against Covid-19 under conditions of war in Ukraine: Problems and prospects

The pandemic of the coronavirus infection Covid-19, which spread around the world in 2020, changed the lives of millions of people and negatively affected the life and functioning conditions of all countries, people and nations without exception. With the emergence of the opportunity to be vaccinated against Covid-19, the problem of making a decision about vaccination also appeared. But recently, it has become increasingly clear that the coronavirus disease in the world is moving into the group of annual viral epidemic diseases that occur every year in different countries during the seasonal wave of acute respiratory viral infections. The ongoing Covid-19 pandemic against the background of the adoption of serious quarantine measures indicates the need for large-scale vaccination of the population as the most effective way to protect against Covid-19. In this article, we pay special attention to vaccination, as the main factor in ensuring health, reducing the morbidity and severity of the course of the Covid-19 disease, and an important task of the state and modern public administration. Plans regarding vaccination, under the conditions of the war in Ukraine, will not be implemented in full - this all the more requires attention to this issue.

College students' influenza vaccination adoption: Self-reported barriers and facilitators

OBJECTIVE

Influenza attack rates among college students are high. However, little is known about the determinants of students' flu vaccine adoption from their own perspectives. To fill this gap, this study aims to investigate barriers and facilitators to college students' flu vaccine adoption.

METHODS

A total of 545 students offered complete answers to an online survey. Thematic analysis was used for analyzing open-ended questions.

RESULTS

Students' flu vaccine adoption was hindered by their fear associated with the flu vaccine, lack of pertinent knowledge, perceived lack of necessity, negative social influence, and time constraints and convenience concerns. Students were motivated to adopt the flu vaccine for their interest in self-care, positive experience with the flu vaccine adoption, good flu vaccine habits, and recommendations from trusted sources.

CONCLUSIONS

Understanding determinants of students' flu vaccine adoption provides the first step in developing tailored health interventions that may increase students' flu vaccine adoption rates.

Trends and factors associated with change in COVID-19 vaccination intent among residents and staff in six Seattle homeless shelters, March 2020 to August 2021

Introduction

Achieving high COVID-19 vaccination coverage in homeless shelters is critical in preventing morbidity, mortality, and outbreaks, however, vaccination coverage remains lower among people experiencing homelessness (PEH) than the general population.

Methods

We conducted a cross-sectional study to retrospectively describe attitudes and identify factors associated with change in COVID-19 vaccination intent among shelter residents and staff during March 2020 - August 2021. To identify factors associated with change in COVID-19 vaccine intent becoming more positive overall compared to other attitudes, we utilized a Poisson model to calculate Risk Ratios with robust standard errors, adjusting for confounding by shelter site and demographic variables determined a priori.

Results

From July 12 - August 2, 2021, 97 residents and 20 staff participated in surveys across six shelters in Seattle King County, Washington. Intent to be vaccinated against COVID-19 increased from 45.3 % (n = 53) when recalling attitudes in March 2020 to 74.4 % (n = 87) as of August 2021, and was similar among residents and staff. Many participants (43.6 %, n = 51) indicated feeling increasingly accepting about receiving a COVID-19 vaccine since March 2020, while 13.7 % (n = 16) changed back and forth, 10.3 % (n = 12) became more hesitant, and 32.5 % (n = 38) had no change in intent. In the model examining the relationship between becoming more positive about receiving a COVID-19 vaccine compared to all other attitudes (n = 116), we found a 57.2 % increase in vaccine acceptability (RR 1.57; 95 % CI: 1.01, 2.45) among those who reported worsening mental health since the start of the pandemic.

Conclusions

Findings highlight opportunities to improve communication with residents and staff about COVID-19 vaccination and support a need for continued dialogue and a person-centered approach to understanding the sociocultural complexities and dynamism of vaccine attitudes at shelters.Clinical Trial Registry Number: NCT04141917.

Factors associated with influenza vaccine noncompliance at a Rural Texas University

Objective: To investigate influenza vaccination rates and perceptions underlying vaccine noncompliance. Participants: Participants included undergraduate students (N = 365) at a rural, medium-sized university in Texas. Methods: Students were anonymously surveyed in the spring of 2018 on demographics, insurance status, perceived barriers of influenza vaccination, and vaccination status. Results: Nearly 90% of students had health insurance; however, only 30% of them received the influenza vaccination annually. The top two reasons for non-vaccination were the low perceived threat (20.20%) and having a busy schedule (11.10%). Having health insurance [OR: 2.84, CI: (1.16, 7.0)] and being in the younger age group (18-24) [OR: 1.98, CI: (1.11, 3.54)] were both positively associated with the annual vaccination status. Conclusion: Health education efforts should be focused on vaccination initiatives that increase awareness about the health benefits and ease of access, especially among the older age groups (> =25 years). Information on myths versus facts should also be disseminated.

COVID-19 and vaccine hesitancy: A longitudinal study

How do attitudes toward vaccination change over the course of a public health crisis? We report results from a longitudinal survey of United States residents during six months (March 16 –August 16, 2020) of the COVID-19 pandemic. Contrary to past research suggesting that the increased salience of a disease threat should improve attitudes toward vaccines, we observed a decrease in intentions of getting a COVID-19 vaccine when one becomes available. We further found a decline in general vaccine attitudes and intentions of getting the influenza vaccine. Analyses of heterogeneity indicated that this decline is driven by participants who identify as Republicans, who showed a negative trend in vaccine attitudes and intentions, whereas Democrats remained largely stable. Consistent with research on risk perception and behavior, those with less favorable attitudes toward a COVID-19 vaccination also perceived the virus to be less threatening. We provide suggestive evidence that differential exposure to media channels and social networks could explain the observed asymmetric polarization between self-identified Democrats and Republicans.

Influenza Vaccination Among U.S. College or University Students: A Systematic Review

OBJECTIVE

Influenza is one of the major causes of morbidity. This study summarized major components that influence college/university students' use of the vaccination using Ecological System Theory; and evaluated racial differences in key predictors of influenza vaccination/intention.

DATA SOURCE

Sixteen engines (e.g., PsycINFO, Academic Search Premier, Science Citation Index) were used to search for cross-sectional studies (2009-2019).

STUDY INCLUSION/EXCLUSION CRITERIA

PI/CO criteria were applied (U.S. students, multidimensional ecological system, influenza vaccination/intention).

DATA EXTRACTION

25 cross-sectional studies were included from the initial 810 citations. Four reviewers performed the cross-checking.

DATA SYNTHESIS AND RESULTS

Higher SES (e.g., education, vaccine affordability, healthcare resource) were positively associated with vaccination/intention. Under micro levels, both internal factors (e.g., positive beliefs, perceptions, attitudes) and external factors (e.g., supports/recommendations from physicians, families or peers, information, engagement in campus activities) enhanced influenza vaccination/intention of students. Meso level factors (private university, dorm-residence, or student housing) also influenced influenza vaccination/intention. Despite limited information on the effects of race on influenza vaccination, the current study synthesized the racial variances in vaccination behaviors of students.

CONCLUSIONS

Enhancing positive beliefs, perceptions, or attitudes toward influenza vaccination with students is critical. Information about the safety and effectiveness of vaccination could be provided for students through official media, medical sources/physicians, campaigns, or internet websites. Family-to-student or peer-to-peer awareness campaigns could facilitate the vaccination of students.

Increasing Intent to Vaccinate for Seasonal Influenza

Background: The community college student is not currently armed with the resources or prevention information regarding influenza. Less than twenty percent of the college population receives influenza immunization annually.Purpose: The purpose of the project was to evaluate if an evidenced-based influenza and vaccine education intervention will affect nursing students' intent to vaccinate for influenza by increasing knowledge of the influenza vaccine using Zingg and Siegrist's Knowledge Scale.Methods: Participants were recruited voluntarily from their attendance at orientation for incoming nursing students on a specific date and time. Utilizing a computer survey, all seventy-seven participants completed an online pretest before an educational intervention, and then, the results were compared following the educational intervention with a posttest. Parametric tests such as a paired t-test, Pearson's correlation coefficient, one-way analysis of variance (ANOVA), and percent change were utilized to determine whether an educational intervention was effective in improving influenza knowledge and whether there was a change in vaccination intention.Outcomes and Results: The educational intervention in this project resulted in enhancement of influenza knowledge. The implications of this project demonstrated the value of providing an educational intervention to improve knowledge, intent, and willingness to vaccinate for influenza for nursing students at a community college.

Effects of Facebook Comments on Attitude Toward Vaccines: The Roles of Perceived Distributions of Public Opinion and Perceived Vaccine Efficacy

This study investigated if and how exposure to Facebook comments about vaccines influences one's attitude toward the vaccines. In this investigation, comments were examined in light of their effect on attitude toward vaccines through perceived distribution of public opinion on vaccines, and perceived vaccine efficacy was tested as a factor moderating relative effects of comments on perception of public opinion distributions. Results from an experimental study (N = 271) showed that exposure to a greater number of comments in a thread expressing (un)favorable opinions on the flu vaccine led to (un)favorable attitude toward the flu vaccine through a change in perceived distribution of public opinions on the vaccination. The indirect effect of comments on attitude toward the flu vaccine through perceived public opinion distributions was greater among participants with lower levels of perceived vaccine efficacy, while the direct effect of comments on attitude was not significant.

Exploring Influenza Vaccine Uptake and Its Determinants among University Students: A Cross-Sectional Study

While vaccination is the only established option to prevent a susceptible host from influenza, we have yet to clarify the decision-making mechanisms of vaccine uptake among Japanese university and college students. We aimed to explore vaccination coverage and the related demographic, sociocultural, and socioeconomic factors among university students. We performed a cross-sectional survey involving 604 students at Hokkaido University. Participants were asked if they received influenza vaccination in advance of the 2018/19 season, and subsequently, their demographic and sociocultural/socioeconomic characteristics were surveyed. We also explored the mechanisms underlying students’ vaccination decisions. Vaccination coverage was estimated at 27.3% (95% confidence interval: 23.7–30.9). Freshmen (p < 0.0001) were significantly associated with choosing vaccination, and their odds ratio of vaccination was 11.3 (95% confidence interval: 6.2–20.7) times greater than students in other years. Among students other than freshmen, students belonging to medicine- and healthcare-related faculties were vaccinated three times more frequently than other students, and the coverage in students from Hokkaido was twice as large as that for students from other prefectures. Moreover, extracurricular activity was a positive predictor of vaccination. Although the coverage was as small as 27.3% among university students, freshmen in Japan have high vaccination coverage, which we believe is associated with the entrance examination during high influenza activity. In addition to exposing students to proper education regarding their risk self-assessment, consciousness raising via appropriate understanding of influenza and its severity and offering vaccination at university health centers at a reasonable cost may promote vaccine acceptance.

Attitudes and barriers associated with seasonal influenza vaccination uptake among public health students; a cross-sectional study

Background

Although research has explored influenza vaccination uptake among medical and college students, there is a dearth of research in understanding influenza vaccination uptake and attitudes toward the vaccine among future public health practitioners. Undergraduate public health students represent future public health practitioners who may be a significant educational resource for health information, including the importance of vaccinations.

Methods

This cross-sectional study utilized survey data from 158 undergraduate public health students attending a large public university in Southern California. The survey assessed public health students’ attitudes and beliefs towards the seasonal influenza vaccine and seasonal vaccination rates among this population.

Results

Over 88% of respondents reported having been encouraged to receive the seasonal influenza vaccine, while only 43.0% reported receipt. Of the students who reported not receiving the vaccine, 49.4% believed it may give them the flu, 30.4% believed there may be dangerous side effects, and 28.9% believed they were not at risk for contracting the flu. Access to health care practitioners (OR: 3.947, 95% CI [1.308–11.906]) and social encouragement (OR: 3.139, 95% CI [1.447–6.811]) were significantly associated with receipt of the seasonal influenza vaccine.

Conclusion

As public health program curriculum includes information about seasonal influenza vaccination and 68% of the sample were seniors soon to be exiting the program with an undergraduate degree in public health education, this low seasonal influenza vaccination rate is disturbing. This study may add to the body of data demonstrating how knowledge of the vaccine does not always guarantee vaccine uptake. Results of the current study suggest that it may be beneficial to provide additional information targeted to public health students, aimed at mediating safety concerns and increasing social pressure to assist in improving vaccine acceptance and rates in this population. Maximizing seasonal influenza vaccination uptake by addressing attitudes, barriers and misperceptions may not only improve vaccination rates among public health students, but also in communities served by these future public health practitioners.

Community health workers on a college campus: Effects on influenza vaccination

OBJECTIVE

To assess the impact of a campus community health worker program (HealthPALs) on student influenza vaccination.

PARTICIPANTS

Undergraduate students at a northeastern US university (enrollment 6650), influenza seasons 2011-2012 through 2015-2016.

METHODS

Study design: Difference-in-differences analysis of student vaccination at campus dormitory influenza clinics during intervention vs. baseline.

INTERVENTION

In the first intervention year, HealthPALs conducted in-person peer outreach at several campus dormitory flu clinics. Subsequent years, HealthPALs conducted an enhanced intervention, with the addition of a personalized, dormitory-specific social media campaign appealing to students' community identity.

RESULTS

The initial intervention increased vaccinations by 66% (IRR = 1.66, 95%CI 1.39-1.97) at intervention clinics relative to control. The enhanced intervention increased vaccinations by 85% (IRR = 1.85, 95%CI 1.75-1.96).

CONCLUSION

Community health workers can be a highly effective, low-cost strategy for increasing influenza vaccination among college students. This model could also be used to address other campus health challenges where student engagement is key.

Freshman Flu Vaccination Behavior and Intention During a Nonpandemic Season

Objective. To examine predictors of flu vaccination and vaccination intention among college freshmen during a nonpandemic influenza season using the health belief model (HBM). Participants. A total of 184 college freshmen at a single institution participated in a mixed-mode (paper or online) survey in October-November 2015. Method. Flu vaccination and intention to vaccinate were predicted using binomial logistic regression on HBM constructs (perceived susceptibility, severity, benefits, barriers, cues to action, and availability), prior flu vaccination history, family and peer reference behaviors, and demographics. Results. Overall, 31.5% of participants received the seasonal flu vaccine by mid-November, and 25% intended to receive it. In full models, history of past flu vaccination (adjusted odds ratio [aOR] = 7.90; 95% confidence interval [CI] = 2.55-24.49) was significant for vaccination while availability (aOR = 2.00; 95% CI = 1.32-3.01) and family intention (aOR = 250.59; 95% CI = 3.77 to >999) were positively associated with intent to vaccinate. Significant confounding by past behavior and family intentions existed for both outcomes. Conclusions. Past flu vaccination behavior and family member intentions to vaccinate were better predictors of annual flu vaccination behavior and intention than HBM constructs among college freshmen. College campuses may enhance flu vaccine coverage by highlighting benefits and availability to students and families.

Barriers of Influenza Vaccination Intention and Behavior - A Systematic Review of Influenza Vaccine Hesitancy, 2005 - 2016

BACKGROUND

Influenza vaccine hesitancy is a significant threat to global efforts to reduce the burden of seasonal and pandemic influenza. Potential barriers of influenza vaccination need to be identified to inform interventions to raise awareness, influenza vaccine acceptance and uptake.

OBJECTIVE

This review aims to (1) identify relevant studies and extract individual barriers of seasonal and pandemic influenza vaccination for risk groups and the general public; and (2) map knowledge gaps in understanding influenza vaccine hesitancy to derive directions for further research and inform interventions in this area.

METHODS

Thirteen databases covering the areas of Medicine, Bioscience, Psychology, Sociology and Public Health were searched for peer-reviewed articles published between the years 2005 and 2016. Following the PRISMA approach, 470 articles were selected and analyzed for significant barriers to influenza vaccine uptake or intention. The barriers for different risk groups and flu types were clustered according to a conceptual framework based on the Theory of Planned Behavior and discussed using the 4C model of reasons for non-vaccination.

RESULTS

Most studies were conducted in the American and European region. Health care personnel (HCP) and the general public were the most studied populations, while parental decisions for children at high risk were under-represented. This study also identifies understudied concepts. A lack of confidence, inconvenience, calculation and complacency were identified to different extents as barriers to influenza vaccine uptake in risk groups.

CONCLUSION

Many different psychological, contextual, sociodemographic and physical barriers that are specific to certain risk groups were identified. While most sociodemographic and physical variables may be significantly related to influenza vaccine hesitancy, they cannot be used to explain its emergence or intensity. Psychological determinants were meaningfully related to uptake and should therefore be measured in a valid and comparable way. A compendium of measurements for future use is suggested as supporting information.

Zika virus knowledge, attitudes, and vaccine interest among university students

BACKGROUND

Zika virus vaccine development is underway. We examined interest in receiving a Zika virus vaccine (after one becomes commercially available) among students at a large public university in Northern Virginia.

METHODS

An online survey of Zika virus-related knowledge, attitudes, and interest in receiving a Zika vaccine was completed by 619 undergraduate students in April, 2016. Stepwise logistic regression with backward elimination was used to identify the variables most strongly associated with interest in being vaccinated against Zika virus.

RESULTS

More than half of participants (52.8%) reported that they would be likely or very likely to be vaccinated against Zika virus. Vaccination interest was significantly higher among participants who received an influenza vaccine in the past year (p=0.002), had higher levels of knowledge about Zika virus (p=0.046), reported knowing where to access information about Zika virus (p=0.041), had higher perceived susceptibility to Zika virus (p<0.001), and believed that the U.S. Government should prioritize actions to control Zika virus (p=0.001).

CONCLUSIONS

Communication and intervention strategies encouraging vaccine uptake may benefit from increasing knowledge of Zika virus, addressing perceived susceptibility, and reaching students, travelers, and others who may be seeking information about prevention of Zika virus and other emerging infectious diseases.

Factors influencing the decision to comply with nurse recommendations to take or avoid influenza vaccination

Influenza is a major cause of morbidity and mortality. Although vaccination is an efficient means of prevention, low rates of vaccination are reported periodically. The study aimed to examine factors affecting acceptance of nurses' recommendations to take or avoid influenza vaccination. Study design was quasi-experimental with a 2 × 2 between subjects design: two variables were manipulated and two were not. The research variables were expertise (of nurses and respondents), type of recommendation (to vaccinate or not) and respondents' a-priori intention to vaccinate. Data were collected from 374 respondents. The study was scenario based, differing in nurse expertise and type of recommendation. After each scenario, the respondents were requested to indicate their a-priori intention to vaccinate and to complete questionnaires on epistemic authority (EA) attributed to the nurse, and of self-epistemic authority (SEA). There is a general tendency to avoid vaccination. Intention to vaccinate correlated positively with nurse recommendations, respondent a-priori intention and nurse expertise. A significant three-way interaction between respondents' SEA, nurse recommendations and nurse expertise was found. The nurse's recommendation has the strongest effect when the nurse is an expert and the respondent perceives him/herself as having high self-EA. The results highlight the importance of patients' sense of knowledge for assuring their co-operation and compliance with medical recommendations.

Barriers Associated with Seasonal Influenza Vaccination among College Students

Influenza can spread rapidly on college campuses because of high-density living conditions and frequent social interactions. However, seasonal influenza vaccination rates on college campuses are low. The purpose of this study is to identify barriers associated with receipt of the seasonal influenza vaccination. Questionnaires were completed by a convenience sample of 383 undergraduate students in January 2014. Data were analyzed to identify barriers associated with receiving the seasonal influenza vaccine. Only 20.6% of students reported receiving the vaccine within the last 6 months. Among students who did not receive the vaccine, 47.8% believed they would get influenza from the vaccine, 41.6% believed the vaccination may have dangerous side effects, and 39.6% believed they were not at risk for contracting influenza. The majority of nonvaccinated students did not believe cost of the vaccine or access to the vaccine were barriers. Many college students are not receiving the seasonal influenza vaccine, representing an important area for improvement. Understanding potential barriers associated with receipt of this vaccine is important for identifying and creating effective public health education programs and campaigns. There is a need for enhanced vaccination education efforts among college students, particularly with respect to the safety and importance of this vaccine.

Increasing herd immunity with influenza revaccination

Seasonal influenza is a significant public health concern globally. While influenza vaccines are the single most effective intervention to reduce influenza morbidity and mortality, there is considerable debate surrounding the merits and consequences of repeated seasonal vaccination. Here, we describe a two-season influenza epidemic contact network model and use it to demonstrate that increasing the level of continuity in vaccination across seasons reduces the burden on public health. We show that revaccination reduces the influenza attack rate not only because it reduces the overall number of susceptible individuals, but also because it better protects highly connected individuals, who would otherwise make a disproportionately large contribution to influenza transmission. We also demonstrate that our results hold on an empirical contact network, in the presence of assortativity in vaccination status, and are robust for a range of vaccine coverage and efficacy levels. Our work contributes a population-level perspective to debates about the merits of repeated influenza vaccination and advocates for public health policy to incorporate individual vaccine histories.

Low uptake of influenza vaccine among university students: evaluating predictors beyond cost and safety concerns

INTRODUCTION

Annual influenza vaccine coverage for young adults (including college students) remains low, despite a 2011 US recommendation for annual immunization of all people 6 months and older. College students are at high risk for influenza morbidity given close living and social spaces and extended travel during semester breaks when influenza circulation typically increases. We evaluated influenza vaccine uptake following an on-campus vaccine campaign at a large, public New York State university.

METHODS

Consecutive students visiting the University Health Center were recruited for a self-administered, anonymous, written survey. Students were asked about recent influenza vaccination, barriers to influenza vaccination, and willingness to get vaccinated to protect other vulnerable individuals they may encounter. Frequencies and proportions were evaluated.

RESULTS

Of 653 students approached, 600 completed surveys (92% response proportion); respondents were primarily female (61%) and non-Hispanic white (59%). Influenza vaccine coverage was low (28%). Compared to coverage among non-Hispanic white students (30%), coverage was similar among Hispanic (30%) and other race/ethnicity students (28%) and lowest among non-Hispanic black students (17%). Among the unvaccinated, the most commonly selected vaccination barriers were "Too lazy to get the vaccine" (32%) and "Don't need the vaccine because I'm healthy" (29%); 6% of unvaccinated students cited cost as a barrier. After being informed that influenza vaccination of young, healthy people can protect other vulnerable individuals (e.g., infants, elderly), 71% of unvaccinated students indicated this would increase their willingness to get vaccinated.

CONCLUSIONS

Influenza vaccine uptake among college students is very low. While making vaccine easily obtained may increase vaccine uptake, college students need to be motivated to get vaccinated. Typically healthy students may not perceive a need for influenza vaccine. Education about vaccinating healthy individuals to prevent the spread of influenza to close contacts, such as vulnerable family members, may provide this motivation to get vaccinated.

Factors associated with influenza vaccine receipt in community dwelling adults and their children

BACKGROUND

Factors associated with influenza vaccine receipt are well studied in healthcare personnel, pregnant women, and the elderly. There has been substantially less research in community dwelling adults and children, and none among entire households. Many studies determine vaccination status by self-report or behavioral intention, outcomes susceptible to misclassification. Given that vaccine is recommended for everyone over six months, re-evaluating these factors is warranted.

METHODS

The Household Influenza Vaccine Effectiveness (HIVE) study is a prospective cohort of households with children. In 2010-2011, 549 adults representing 312 households completed surveys evaluating knowledge, attitudes, and practices regarding influenza vaccination for themselves and their children. Using the health belief model (HBM) as a framework, we examined factors associated with documented seasonal influenza vaccine receipt using log-binomial regression models.

RESULTS

In multivariate models, cues to action such as doctor recommendation, (RR 1.62, 95% CI: 1.25-2.10), perceived benefits (RR 1.25, 95% CI: 1.04-1.50), and perceived susceptibility (RR 1.21, 95% CI: 1.03-1.42) were significantly associated with increased likelihood of vaccine receipt among adults while high perceived barriers were associated with decreased likelihood (RR 0.38, 95% CI: 0.25-0.59). Similarly, parents reporting higher barriers were less likely (RR 0.58, 95% CI: 0.42-0.79) and those perceiving greater benefits (RR 4.16, 95% CI: 2.28-7.59) and severity (RR 1.13, 95% CI: 1.00-1.27 were more likely to vaccinate their children. The observed effects of perceptions of susceptibility, severity, and benefits were more pronounced at low cues to action for children, as were the effects of perceptions of barriers and severity among adults.

CONCLUSION

Perceived benefits and barriers are most strongly associated with vaccine receipt. However, the effects of various factors were most pronounced in the absence of cues to action, which may be an important component of targeted interventions.

Effect of the one-child policy on influenza transmission in China: a stochastic transmission model

BACKGROUND

China's one-child-per-couple policy, introduced in 1979, led to profound demographic changes for nearly a quarter of the world's population. Several decades later, the consequences include decreased fertility rates, population aging, decreased household sizes, changes in family structure, and imbalanced sex ratios. The epidemiology of communicable diseases may have been affected by these changes since the transmission dynamics of infectious diseases depend on demographic characteristics of the population. Of particular interest is influenza because China and Southeast Asia lie at the center of a global transmission network of influenza. Moreover, changes in household structure may affect influenza transmission. Is it possible that the pronounced demographic changes that have occurred in China have affected influenza transmission?

METHODS AND FINDINGS

To address this question, we developed a continuous-time, stochastic, individual-based simulation model for influenza transmission. With this model, we simulated 30 years of influenza transmission and compared influenza transmission rates in populations with and without the one-child policy control. We found that the average annual attack rate is reduced by 6.08% (SD 2.21%) in the presence of the one-child policy compared to a population in which no demographic changes occurred. There was no discernible difference in the secondary attack rate, -0.15% (SD 1.85%), between the populations with and without a one-child policy. We also forecasted influenza transmission over a ten-year time period in a population with a two-child policy under a hypothesis that a two-child-per-couple policy will be carried out in 2015, and found a negligible difference in the average annual attack rate compared to the population with the one-child policy.

CONCLUSIONS

This study found that the average annual attack rate is slightly lowered in a population with a one-child policy, which may have resulted from a decrease in household size and the proportion of children in the population.

[Vaccination coverage in German adults: results of the German Health Interview and Examination Survey for Adults (DEGS1)]

In the absence of an immunisation register, vaccination coverage in Germany must be estimated. Ten years after the German National Health Interview and Examination Survey 1998 (GNHIES98), the population survey DEGS1 is one of the data sources to be used for monitoring vaccination coverage. In the survey, data on vaccination history were obtained from vaccination cards and self-reports. The prevalence of immunisation for tetanus and diphtheria was higher compared to the prevalence estimated ten years previously in GNHIES98. Nonetheless, 28.6 % of adults have not been vaccinated against tetanus and 42.9 % have not been vaccinated against diphtheria within the last ten years. Vaccination is especially low among the elderly, among adults with low socio-economic status and in western Germany. During the last ten years, only 11.8 % of women and 9.4 % of men were vaccinated against pertussis in western Germany; vaccination coverage was twice as high in eastern Germany. In 2009, recommendations were published to combine the next tetanus immunisation with a pertussis immunisation; therefore pertussis vaccination coverage might improve in the coming years. The lifetime prevalence of influenza vaccination obtained in DEGS1 is higher than the annual vaccination rate for influenza. However, the lifetime prevalence among adults aged 60 years or older is still below the annual rate of 75 % recommended by the WHO. An English full-text version of this article is available at SpringerLink as supplemental.

Disparities in the severity of influenza illness: a descriptive study of hospitalized and nonhospitalized novel H1N1 influenza-positive patients in New York City: 2009-2010 influenza season

OBJECTIVE

To investigate the association between socioeconomic status (SES) and hospitalization for 2009 H1N1 influenza, independently of access to care and known risk factors for severe influenza illness, among New York City residents during the 2009-2010 influenza season.

DESIGN

We used a 1:2 case-control study design, matching by age group and month of diagnosis. Cases were defined as laboratory-confirmed patients with 2009 H1N1 influenza who were hospitalized during their illness. Controls were defined as nonhospitalized laboratory-confirmed influenza A patients. Participants were contacted for a telephone interview to collect relevant clinical and demographic data. We used conditional logistic regression to analyze the association between SES and hospitalization.

SETTING

New York City.

PARTICIPANTS

Of the 171 hospitalized cases who were identified between October 2009 and February 2010, a total of 128 completed telephone interviews. A total of 640 nonhospitalized controls were contacted, and of these, 337 completed interviews.

MAIN OUTCOME MEASURES

The main outcome of interest was whether or not a patient was hospitalized during his or her 2009 H1N1 influenza illness. Socioeconomic status was measured using education and neighborhood poverty.

RESULTS

We identified a gradient in the odds of hospitalization for 2009 H1N1 influenza by education level among adults. This association could not be entirely explained by access to care and underlying risk factors. An inverse association between odds of hospitalization and neighborhood poverty was also identified among adults and children.

CONCLUSIONS

This study suggests that individuals of lower SES were more vulnerable to severe illness during the 2009 H1N1 pandemic. Additional research is needed to help guide interventions to protect this population during future influenza pandemics.

Inter-state variation in human papilloma virus vaccine coverage among adolescent girls in the 50 US states, 2007

Human papilloma virus (HPV) vaccination could substantially reduce the burden of cervical cancer by preventing HPV infection. This study uses the 2007 National Survey of Children's Health (NSCH) to estimate HPV vaccine coverage prevalence for US girls aged 12-17, the target group for vaccination. NSCH is a population-based telephone survey of households with children younger than 18 years. The proportion of girls aged 12-17 whose parent or guardian reported receipt of a clinician recommendation for HPV vaccination, one or more does of HPV vaccine, or a complete three-dose HPV vaccine series were estimated. Multivariable models estimated adjusted associations and marginal predicted vaccine coverage prevalence for each of the 50 US states and according to race/ethnicity, household income, insurance status, parental education, and whether the girl had a 'medical home'. The NSCH sample included 17,264 girls aged 12-17. Overall 18.2 % (SE 0.8 %) of girls reportedly received at least one HPV vaccine dose and 3.6 % (SE 0.4 %) completed the series; 31 % received clinician recommendation for HPV vaccine. Girls who received a clinician recommendation to vaccinate were 23 (95 % CI 18-29) times as likely to be vaccinated as those not counseled. There was substantial interstate variation in vaccine coverage that was largely explained by variability in clinician counseling. For 2007, there was substantial variation in HPV vaccine coverage among US girls 12-17 years that was largely explained by variability in clinician counseling. Strategies aimed at increasing clinicians' counseling for HPV vaccination could substantially reduce disparities in HPV vaccine coverage.

The potential effect of temporary immunity as a result of bias associated with healthy users and social determinants on observations of influenza vaccine effectiveness; could unmeasured confounding explain observed links between seasonal influenza vaccine and pandemic H1N1 infection?

BACKGROUND

Five observational studies from Canada found an association between seasonal influenza vaccine receipt and increased risk of pandemic influenza H1N1 2009 infection. This association remains unexplained. Although uncontrolled confounding has been suggested as a possible explanation, the nature of such confounding has not been identified. Observational studies of influenza vaccination can be affected by confounding due to healthy users and the influence of social determinants on health. The purpose of this study was to investigate the influence that these two potential confounders may have in combination with temporary immunity, using stratified tables. The hypothesis is that respiratory virus infections may activate a temporary immunity that provides short-term non-specific protection against influenza and that the relationship with being a healthy user or having a social determinant may result in confounding.

METHODS

We simulated the effect of confounding on vaccine effectiveness assuming that this could result from both social determinants and healthy user effects as they both influence the risk of seasonal influenza and non-influenza respiratory virus infections as well as the likelihood of being vaccinated. We then examined what impact this may have had on measurement of seasonal influenza vaccine effectiveness against pandemic influenza.

RESULTS

In this simulation, failure to adjust for healthy users and social determinants would result in an erroneously increased risk of pandemic influenza infection associated with seasonal influenza vaccination. The effect sizes were not however large.

CONCLUSIONS

We found that unmeasured healthy user effects and social determinants could result in an apparent association between seasonal influenza vaccine and pandemic influenza infection by virtue of being related to temporary immunity. Adjustment for social determinants of health and the healthy user effects are required in order to improve the quality of observational studies of influenza vaccine effectiveness.

A national study of individuals who handle migratory birds for evidence of avian and swine-origin influenza virus infections

BACKGROUND

Persons with occupational or recreational exposure to migratory birds may be at risk for infection with highly pathogenic avian influenza and other avian influenza viruses since wild birds are the natural reservoir of influenza A. Additionally, bird handlers may host avian and swine-origin influenza (pH1N1) virus co-infections, which generate reassortant viruses with high pathogenicity in mammals.

OBJECTIVES

We assessed the prevalence of avian and swine influenza viruses in US-based bird handlers and estimated their exposure to different orders of wild birds including waterfowl (Anseriformes), songbirds (Passeriformes), and shorebirds (Charadriiformes).

STUDY DESIGN

Cross-sectional serologic survey accompanied by a questionnaire to estimate behavioral risk factors. This is first survey of US-based bird handlers who also work at international sites.

RESULTS

401 participants were recruited and tested over the course of 3 years. One participant with occupational exposure to migratory birds had evidence of past infections with a H5N2 virus antigenically related to A/Nopi/MN/07/462960-02, which is the first case of this influenza subtype in a human host associated with exposure to wild rather than domestic birds. We detected no avian and swine-origin influenza virus co-infections. The exposure of bird handlers to songbirds was four times greater than to shorebirds or waterfowl.

CONCLUSIONS

Though rare, the transmission of avian influenza viruses from migratory birds to US-based bird handlers has potentially significant public health and economic consequences.

2009-2010 seasonal influenza vaccination coverage among college students from 8 universities in North Carolina

OBJECTIVE

The authors sought to describe the 2009-2010 seasonal influenza vaccine coverage of college students.

PARTICIPANTS

A total of 4,090 college students from 8 North Carolina universities participated in a confidential, Web-based survey in October-November 2009.

METHODS

Associations between self-reported 2009-2010 seasonal influenza vaccination and demographic characteristics, campus activities, parental education, and e-mail usage were assessed by bivariate analyses and by a mixed-effects model adjusting for clustering by university.

RESULTS

Overall, 20% of students (range 14%-30% by university) reported receiving 2009-2010 seasonal influenza vaccine. Being a freshman, attending a private university, having a college-educated parent, and participating in academic clubs/honor societies predicted receipt of influenza vaccine in the mixed-effects model.

CONCLUSIONS

The self-reported 2009-2010 influenza vaccine coverage was one-quarter of the 2020 Healthy People goal (80%) for healthy persons 18 to 64 years of age. College campuses have the opportunity to enhance influenza vaccine coverage among its diverse student populations.

Evaluation of the seroprevalence of influenza A(H1N1) 2009 on a university campus: a cross-sectional study

BACKGROUND

Human infection with influenza A(H1N1) 2009 was first identified in the United States on 15 April 2009 and on 11 June 2009, WHO declared that the rapidly spreading swine-origin influenza virus constituted a global pandemic. We evaluated the seroprevalence of influenza A(H1N1) 2009 virus on a large public University campus, as well as disparities in demographic, symptomatic and vaccination characteristics of participants.

METHODS

Using a cross-sectional study design, sera was collected from volunteers and then tested for the presence of antibodies to the virus using a ≥ 1:40 dilution cut-off by hemagglutination inhibition assay. In conjunction, participants were asked to complete a questionnaire allowing us to estimate risk factors for infection in this population, as well as distinguish artificially derived antibodies from naturally derived antibodies.

RESULTS

300 total participants were recruited and tested. 158 (52.6%) tested positive for influenza A(H1N1) 2009 via hemagglutination inhibition assay using a ≥ 1:40 dilution cut-off. 86 people (54.4%) tested positive for H1N1 but did not report experiencing symptoms during the pandemic meeting the May 2010 CDC definition of influenza-like illness. Furthermore, of those individuals who reported that they had received the H1N1 vaccine, 16% did not test positive.

CONCLUSIONS

Overall, 52.7% of the total study population tested positive for influenza A(H1N1) 2009. 54.4% of those who tested positive for influenza A(H1N1) 2009 using the ≥ 1:40 dilution cut-off on the hemagglutination inhibition assay in this study population did not report experiencing symptoms during the pandemic meeting the May 2010 CDC definition of influenza-like illness. 16% of those who reported receiving the H1N1 vaccine did not test positive by HAI. We also found that vaccination coverage for H1N1 vaccine was poor among Blacks and Latinos, despite the fact that vaccine was readily available at no cost.

Determinants of tetanus and seasonal influenza vaccine uptake in adults living in Germany

The primary objective of this study was to assess determinants of vaccine uptake in adults living in Germany exemplified by one standard vaccination (tetanus) and one vaccination targeting specific risk-groups (seasonal influenza). Data from 21,262 telephone household-interviews representative of the adult population in Germany were collected in 2009 and analysed. A total 73.1% of the adult population had a sufficient tetanus vaccination status according to national recommendations (i.e. last tetanus shot ≤10 years ago). Influenza vaccination coverage in the target population (i.e. persons ≥60 years, chronically ill, healthcare workers) was 44.1%. Persons who received professional vaccination advice within the past five years were more frequently vaccinated against tetanus and influenza than persons without (p< 0.001). Private physicians were identified as the most important source for vaccination advice. Having a statutory health insurance, last physician contact < 1 year ago, and living in the eastern part of Germany were independently associated with higher tetanus and influenza vaccine uptake. Low socio-economic status, two-sided migration background, and the feeling of being insufficiently informed on the benefits of vaccination were independently associated with low uptake of tetanus but not influenza vaccines. Our results show that tetanus vaccination coverage in the general adult population and influenza vaccination coverage in the target population are unsatisfactorily low in Germany. Since physicians' advice has a major impact on the vaccination decision, physician reminder systems could provide a method to increase vaccination coverage in adults. For tetanus, information activities should target population groups with an increased risk of being undervaccinated.

College students' perceptions of H1N1 flu risk and attitudes toward vaccination

College students are highly susceptible to the H1N1 virus, yet previous studies suggest that college students perceive themselves at low risk for the flu. We surveyed 514 undergraduates to assess their perceptions of H1N1 flu risk and opinions about flu vaccines. A third of respondents stated that they were not at risk of getting the H1N1 flu because they were young. Responses indicated a distrust of the safety and effectiveness of influenza vaccinations; only 15.8% of participants planned on receiving H1N1 vaccination. Top reasons for refusing the H1N1 vaccine included questioning vaccine safety and effectiveness, and concerns about potential serious and/or benign side effects. Top reasons for H1N1 vaccination acceptance included receiving a doctor recommendation for the vaccine, having previously gotten a seasonal vaccine, and being at high-risk for influenza. Our findings suggest that college students are inaccurate in assessing their risk level and are unlikely to seek vaccinations.