Gender influence in influenza vaccine uptake in Spain: time trends analysis (1995-2006)

Insufficient vaccine coverage and vaccine hesitancy in people living with HIV: A prospective study in outpatient clinics in the Paris region

Vaccine prevention strategies play a crucial role in the management of people living with HIV (PLWH). The aim of this study was to assess vaccination coverage and identify barriers to vaccine uptake in PLWH in the Paris region. A cross-sectional survey was conducted in PLWH in 16 hospitals in the Paris region. The vaccination status, characteristics, opinions, and behaviors of participants were collected using a face-to-face questionnaire and from medical records. A total of 338 PLWH were included (response rate 99.7 %). The median age of participants was 51 years (IQR: 41-58). Vaccination coverage was 77.3 % for hepatitis B (95 % CI: 72.3-81.8 %), 62.7 % for hepatitis A (57.3-67.9 %), 61.2 % for pneumococcal vaccines (55.8-66.5 %), 56.5 % for diphtheria/tetanus/poliomyelitis (DTP) (51.0-61.9 %), 44.7 % for seasonal influenza (39.3-50.1 %), 31.4 % for measles/mumps/rubella (26.4-36.6 %) and 38.5 % for meningococcal vaccine (13.9-68.4 %). The main reason for vaccine reluctance was related to the lack of vaccination proposals/reminders. The overall willingness to get vaccinated was 71.0 % (65.9-75.8 %). In the multivariable analysis, several factors were associated with a higher vaccine uptake; for DTP vaccine: higher education level, having vaccination records, being registered with a general practitioner; for seasonal influenza vaccine: age > 60 years, higher education level, being employed. The overall vaccination coverage was suboptimal. Development of strategies reducing missed opportunity to offer vaccines is needed.

Sex and gender differences in adverse events following receipt of influenza and COVID-19 vaccination among healthcare workers

Introduction

Active and passive surveillance studies have found that a greater proportion of females report adverse events (AE) following receipt of either the COVID-19 or seasonal influenza vaccine compared to males. We sought to determine the intersection of biological sex and sociocultural gender differences in prospective active reporting of vaccine outcomes, which remains poorly characterized.

Methods

This cohort study enrolled Johns Hopkins Health System healthcare workers (HCWs) who were recruited from the annual fall 2019-2022 influenza vaccine and the fall 2022 COVID-19 bivalent vaccine campaigns. Vaccine recipients were enrolled the day of vaccination and AE surveys were administered two days post-vaccination (DPV) for bivalent COVID-19 and Influenza vaccine recipients. Data were collected regarding the presence of a series of solicited local and systemic AEs. Open-ended answers about participants' experiences with AEs also were collected for the COVID-19 vaccine recipients.

Results

Females were more likely to report local AEs after influenza (OR=2.28, p=0.001) or COVID-19 (OR=2.57, p=0.008) vaccination compared to males, regardless of age or race. Males and females had comparable probabilities of reporting systemic AEs after influenza (OR=1.18, p=0.552) or COVID-19 (OR=0.96, p=0.907) vaccination. Exogenous hormones from birth control use did not impact the rates of reported AEs following COVID-19 vaccination among reproductive-aged female HCWs. Women reported more interruptions in their daily routine following COVID-19 vaccination than men and were more likely to seek out self-treatment. More women than men scheduled their COVID-19 vaccination before their days off in anticipation of AEs.

Conclusions

Our findings highlight the need for sex- and gender-inclusive policies to inform more effective occupational health vaccination strategies. Further research is needed to evaluate the potential disruption of AEs on occupational responsibilities following mandated vaccination for healthcare workers and to more fully characterize the post-vaccination behavioral differences between men and women.

KEY MESSAGE

What is already known on this topic: ⇒ Among diversely aged adults 18-64 years, females report more AEs to vaccines, including the influenza and COVID-19 vaccines, than males.⇒ Vaccine AEs play a role in shaping vaccine hesitancy and uptake.⇒ Vaccine uptake related to influenza and COVID-19 are higher among men than women.⇒ Research that addresses both the sex and gender disparities of vaccine outcomes and behaviors is lacking.What this study adds: ⇒ This prospective active reporting study uses both quantitative and qualitative survey data to examine sex and gender differences in AEs following influenza or COVID-19 vaccination among a cohort of reproductive-aged healthcare workers.How this study might affect research, practice, or policy: ⇒ Sex and gender differences in AEs and perceptions relating to vaccination should drive the development of more equitable and effective vaccine strategies and policies in occupational health settings.

Using the theory of planned behavior to assess willingness and attitudes towards COVID-19 vaccination among a predominantly white U.S. college sample

Objective

Through the lens of behavioral models such as the Theory of Planned Behavior (TPB) and the Health Belief Model, the present study (1) investigated U.S. university students' willingness to receive the COVID-19 vaccine and (2) examined predictors (e.g. demographics, past vaccine experience, TPB constructs) of vaccine willingness.

Method

University students (n = 170) completed a survey assessing demographics, health behaviors, attitudes, perceived severity/susceptibility, norms, and vaccine intentions related to the COVID-19 pandemic. Data were collected from April 2020 through July 2020.

Results

Overall, 56.5% of participants indicated that they would be willing to receive the COVID-19 vaccine once it is available, 39.4% were unsure of whether they would receive the vaccine, and 4.1% indicated they would not receive the vaccine. Multinomial logistic regression indicated that greater adherence to CDC guidelines (p = .030) and greater perceived pro-vaccine norms (p < .001) predicted greater vaccine willingness.

Conclusions

Results from this study are consistent with previous literature on vaccine hesitancy, whereby normative beliefs and adherence to CDC guidelines were found to be determinants of vaccine willingness. To reduce transmission of the COVID-19 pandemic, interventions aimed at promoting positive attitudes towards vaccination should aim to incorporate these observed determinants.

Predictors and motives for mask-wearing behavior and vaccination intention

Containing a pandemic requires that individuals adhere to measures such as wearing face-masks and getting vaccinated. Therefore, identifying predictors and motives for both behaviors is of importance. Here, we study the decisions made by a cross-national sample in randomized hypothetical scenarios during the COVID-19 pandemic. Our results show that mask-wearing was predicted by empathic tendencies, germ aversion, and higher age, whilst belief in misinformation and presentation of an interaction partner as a family member lowered the safety standards. The main motives associated with taking the mask off included: rationalization, facilitating interaction, and comfort. Vaccination intention was positively predicted by empathy, and negatively predicted by belief in misinformation and higher costs of the vaccine. We found no effect of immunization status of the surrounding social group. The most common motive for vaccination was protection of oneself and others, whereas undecided and anti-vaccine groups reported doubts about the effectiveness and fear of side effects. Together, we identify social and psychological predictors and motives of mask-wearing behavior and vaccination intention. The results highlight the importance of social context for mask-wearing, easy access to vaccines, empathy, and trust in publicly distributed information.

How cyberchondria and decision self-efficacy shapes the acceptability of COVID-19 vaccine: A gender-based comparison

Objective

Alarmingly, the individuals' reach and coverage to get vaccinated in developing regions during the pandemic is a massive challenge for concerned authorities. This study aimed to demonstrate how cyberchondria play a significant role in a classical health belief model. Cyberchondria may influence cognitive factors (e.g. self-efficacy), which may contribute to an increase in attitude-behavior gap. Especially in the context of a health-centric scenario, it may discourage individuals to take protective measures.

Method

By using the cross-sectional research design, the authors conducted a quantitative survey in Pakistan and collected 563 responses from 303 male respondents (rural = 91; urban = 212) with (Urban M:35.5, standard deviation (SD):13.4) and rural M:37.5, SD:8.4).

Result

The findings indicate that decision self-efficacy among males is stronger than that in females. It dominates other determinants, which can dampen the individuals' intentions to get vaccinated. For instance, the effect of conspiracies and perceived seriousness was noted nonsignificant and weak. In females, perceived seriousness was stronger determinant than in males. In addition, the negative effect of decision self-efficacy was noted in the case of females, and conspiracy and cyberchondria had a negative role.

Conclusion

This study highlights valuable implications for future research in infodemic, health communication and health literacy, and practical implications for regulatory bodies and public administration.

Life Satisfaction and Influenza Vaccination Among Older Adults in Canada

Older adults have an increased risk of complications or death from influenza. Despite the benefits of vaccination for older adults, vaccination coverage among older adults ages 65 years and over is still below Canada's national target of 80 per cent. As health-care-seeking behaviours are influenced by several factors, including life satisfaction, we investigated the relationship between life satisfaction and influenza vaccination among older adults. A sample (n = 22,424) from the 2015-2016 Canadian Community Health Survey data was analysed using descriptive and multinomial logistic regression analyses. Higher life satisfaction was associated with a more recent influenza vaccination history. Vaccination differed by gender, age, and self-reported health status, as women, much older adults, and those with the poorest health status were more likely to be vaccinated. The study suggests an association between life satisfaction and influenza vaccination. More research into the factors that impact influenza vaccination in older adults is needed to increase vaccination coverage in the older adult population.

First COVID-19 Booster Dose in the General Population: A Systematic Review and Meta-Analysis of Willingness and Its Predictors

The emergence of breakthrough infections and new highly contagious variants of SARS-CoV-2 threaten the immunization in individuals who had completed the primary COVID-19 vaccination. This systematic review and meta-analysis investigated, for the first time, acceptance of the first COVID-19 booster dose and its associated factors among fully vaccinated individuals. We followed the PRISMA guidelines. We searched Scopus, Web of Science, Medline, PubMed, ProQuest, CINAHL and medrxiv from inception to 21 May 2022. We found 14 studies including 104,047 fully vaccinated individuals. The prevalence of individuals who intend to accept a booster was 79.0%, while the prevalence of unsure individuals was 12.6%, and the prevalence of individuals that intend to refuse a booster was 14.3%. The main predictors of willingness were older age, flu vaccination in the previous season, and confidence in COVID-19 vaccination. The most important reasons for decline were adverse reactions and discomfort experienced after previous COVID-19 vaccine doses and concerns for serious adverse reactions to COVID-19 booster doses. Considering the burden of COVID-19, a high acceptance rate of booster doses could be critical in controlling the pandemic. Our findings are innovative and could help policymakers to design and implement specific COVID-19 vaccination programs in order to decrease booster vaccine hesitancy.

COVID-19 Vaccine Acceptance among Low- and Lower-Middle-Income Countries: A Rapid Systematic Review and Meta-Analysis

Widespread vaccination against COVID-19 is critical for controlling the pandemic. Despite the development of safe and efficacious vaccinations, low-and lower-middle income countries (LMICs) continue to encounter barriers to care owing to inequitable access and vaccine apprehension. This study aimed to summarize the available data on COVID-19 vaccine acceptance rates and factors associated with acceptance in LMICs. A comprehensive search was performed in PubMed, Scopus, and Web of Science from inception through August 2021. Quality assessments of the included studies were carried out using the eight-item Joanna Briggs Institute Critical Appraisal tool for cross-sectional studies. We performed a meta-analysis to estimate pooled acceptance rates with 95% confidence intervals (CI). A total of 36 studies met the inclusion criteria and were included in the review. A total of 83,867 respondents from 33 countries were studied. Most of the studies were conducted in India (n = 9), Egypt (n = 6), Bangladesh (n = 4), or Nigeria (n = 4). The pooled-effect size of the COVID-19 vaccine acceptance rate was 58.5% (95% CI: 46.9, 69.7, I2 = 100%, 33 studies) and the pooled vaccine hesitancy rate was 38.2% (95% CI: 27.2-49.7, I2 = 100%, 32 studies). In country-specific sub-group analyses, India showed the highest rates of vaccine acceptancy (76.7%, 95% CI: 65.8-84.9%, I2= 98%), while Egypt showed the lowest rates of vaccine acceptancy (42.6%, 95% CI: 16.6-73.5%, I2= 98%). Being male and perceiving risk of COVID-19 infection were predictors for willingness to accept the vaccine. Increasing vaccine acceptance rates in the global south should be prioritized to advance global vaccination coverage.

Time Trends (2012-2020), Sex Differences and Predictors for Influenza Vaccination Uptake among Individuals with Chronic Obstructive Pulmonary Disease in Spain

(1) Background: To analyze time trends, sex differences, and factors associated with influenza vaccination uptake among individuals with COPD in Spain, 2012−2020. (2) Methods: A cross-sectional study based on data from the European Health Surveys for Spain, 2020 (EHSS2020) and 2014 and from the Spanish National Health Interview Surveys for 2017 and 2012. (3) Results: The study included 65,447 participants. Prevalence of COPD was 5.9% (n = 3855). Overall, the influenza vaccination uptake among COPD patients was 57.8% versus 28.6% for those without COPD (p < 0.001). Men with COPD reported higher uptake than women in all the surveys studied. Neither the crude nor the multivariable analysis showed a significant variation change overtime for people with COPD. However, among those aged <65 years, crude uptake decreased from 2012 to 2020 (39.4% vs. 33.3%; p = 0.039). Over the entire period, men were vaccinated significantly more than women (OR 1.28; 95% CI 1.12−1.47). Among COPD participants, included in the EHSS2020, independent predictors of vaccine uptake included being male, higher age, reporting no current smoking and suffering cancer or heart disease. (4) Conclusions: In COPD patients, the influenza vaccination uptake is below desirable levels and did not improve from 2012 to 2020. Sex differences are found, with consistent and constant lower uptake among women with COPD. The observed lower uptake among COPD women and patients with unhealthy lifestyle requires increased attention.

Gender differences in the intention to get vaccinated against COVID-19: a systematic review and meta-analysis

AIM

We conducted a systematic review and meta-analysis to analyse gender differences in COVID-19 vaccination intentions.

SUBJECT AND METHODS

PubMed, Web of Science and PsycInfo were searched (November 2020 to January 2021) for studies reporting absolute frequencies of COVID-19 vaccination intentions by gender. Averaged odds ratios comparing vaccination intentions among men and women were computed. Descriptive analyses of the studies were reported.

RESULTS

Sixty studies were included in the review and data from 46 studies (n = 141,550) were available for meta-analysis. A majority (58%) of papers reported men to have higher intentions to get vaccinated against COVID-19. Meta-analytic calculations showed that significantly fewer women stated that they would get vaccinated than men, OR 1.41 (95% CI 1.28 to 1.55). This effect was evident in several countries, and the difference was bigger in samples of health care workers than in unspecified general population samples.

CONCLUSION

This systematic review and meta-analysis found lower vaccination intentions among women than men. This difference is discussed in the light of recent data on actual vaccination rates in different countries.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s10389-021-01677-w.

Low Levels of Influenza Vaccine Uptake among the Diabetic Population in Spain: A Time Trend Study from 2011 to 2020

(1) Background: In this work, we aim to describe influenza vaccine uptake among the diabetic population in Spain to assess the time trend from 2011 to 2020 and identify predictors of vaccine uptake among diabetes patients. (2) Methods: We conducted a descriptive cross-sectional study using the European Health Interview Survey for Spain (2014 and 2020) and the Spanish National Health Surveys (2011 and 2017). The independent variables analysed included socio-demographic characteristics, health-related variables and lifestyle variables. We matched each participant with diabetes with a non-diabetic participant based on age, sex, place of residence and year of survey. (3) Results: The overall coverage among diabetic adults was 52.1% compared to 40.6% for matched participants without diabetes (p < 0.01). The vaccine uptake among adults with diabetes was 52.6% in 2011, 54.38% in 2014 and 53.4% in 2017. The adjusted OR of having been vaccinated in 2020, with respect to 2011, was not significant at 0.87 (95% CI: 0.72–1.06). Factors such as being male, higher age, being affected by respiratory disease or cancer and being physically active were identified as positive predictors for influenza vaccination uptake, while smoking was a negative predictor. (4) Conclusions: The influenza vaccine uptake is below desirable levels among the adult diabetic population in Spain and has not improved from 2011 to 2020. More efforts should be made to increase influenza vaccine uptake in this high-risk group, especially for women, those aged 18–64 years, without other high-risk conditions and smokers.

Contracting Out National Immunization Program Does Not Improve Vaccination Rate Nor Socioeconomic Inequality: A Case Study of Seasonal Influenza Vaccination in South Korea

The objective of the present study was to investigate if the policy for contracting out the Korean influenza National Immunization Program (NIP) for individuals aged ≥ 65 years affects a reduction in vaccination inequality based on gender and socioeconomic position (SEP). In South Korea, initially only public health centers provided influenza vaccination for free; however, starting from the fall of 2015, the program was expanded to include private medical institutions. The policy was expected to improve overall vaccination rate and reduce its inequality, through improving access to vaccination. The present study analyzed how the gap in the vaccination rate changed between before and after contracting out. A multivariate logistic regression model stratified by gender and SEP of individuals aged ≥ 65 years was used. The study also analyzed changes in the unvaccinated rates between before and after contracting out based on an interrupted time series model. The gap in the unvaccinated rate based on SEP present prior to contracting out of the NIP for individuals aged ≥ 65 years did not decrease afterwards. In particular, the step changes were 0.94% (95% confidence interval [CI]: 0.00, 1.89) and 1.34% (95% CI: 1.17, 1.52) in men and women, respectively. In the pre-policy period, among women, the unvaccinated rate of the medical aid beneficiaries group was 1.22-fold higher (95% CI: 1.12, 1.32) than that of the health insurance beneficiaries, and the difference was not reduced post-policy implementation (odds ratio: 1.27, 95% CI: 1.20, 1.36). The findings of the study were that contracting out of the NIP was not effective in improving vaccination rate nor resolving vaccination inequality. Future studies should focus on identifying the mechanism of vaccination inequality and exploring measures for resolving such inequality.

Intention to get vaccinated against COVID-19 among the general population in France: Associated factors and gender disparities

As the coronavirus disease 2019 (COVID-19) spreads across the world, the rapid distribution of an effective vaccine and its acceptability among the population constitute priorities for health authorities. This study aimed to document attitudes of the general population toward a future vaccine against COVID-19. We used the national COCONEL surveys conducted during the lockdown to identify factors associated with vaccine refusal, in the whole population, and separately among men and women. We investigate the role of socioeconomic and demographic factors as well as exposure to COVID-19. Among the 5,018 participants, 24.0% reported their intention to refuse the vaccine. Thinking this vaccine would not be safe, being against vaccination in general, and perceiving COVID-19 to be harmless were the three main reasons given to explain vaccine refusal. Women were more likely to refuse the vaccine, especially due to a reluctance toward vaccination in general or the perception that a COVID-19 vaccine would not be safe. Some factors associated with the intention to refuse the vaccine were the same among men and women such as a lack of prior vaccination against influenza, and concern over being infected with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), while others differed slightly according to gender such as age, and high prevalence of COVID-19 in their region of residence. Authorities should therefore guarantee that all the necessary precautions are taken before marketing the vaccine and communicate transparently on the process of its development, and on the coverage rate required to reach herd immunity.Abbreviation: EHI: Equivalized Household Income per month; SARS-CoV-2: Severe acute respiratory syndrome coronavirus 2.

COVID-19 vaccination intention in the first year of the pandemic: A systematic review

AIMS AND OBJECTIVES

To synthesise evidence regarding vaccination intention, identify factors contributing to vaccine hesitancy among healthcare professionals and the general populations globally.

BACKGROUND

As COVID-19 vaccine becomes available worldwide, attention is being directed to community vaccine uptake, to achieve population-wide immunity. A number of factors have been reported to influence vaccine intention.

METHODS

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a systematic search of COVID-19 vaccination intention related literature published on or before 31 December 2020 from seven databases was undertaken.

RESULTS

Thirty articles were included in this systematic review. Overall COVID-19 vaccination intention during the first year of the pandemic ranged from 27.7% to 93.3%. Findings highlighted that socio-demographic differences, perceptions of risk and susceptibility to COVID-19 and vaccine attributes influenced vaccination intention. Healthcare professionals particularly, nurses have higher vaccine hesitancy reportedly due to concerns regarding vaccine safety and efficacy and mistrust of health authorities. Negative information about COVID-19 vaccines in the social media and low confidence in the health system were associated with lower acceptability among the community. Interestingly, cumulative increase in COVID-19 caseloads of countries over time was not associated with vaccination intention.

CONCLUSIONS

The significant variability in vaccine intention rates worldwide would hamper efforts to achieve immunity against COVID-19. Nurses' concerns about vaccine safety and efficacy need to be addressed to increase vaccine acceptance and maximise their influence on vaccination decision in the community. As misinformation through social media negatively impacts vaccination uptake, authoritative and reliable information on vaccine attributes, disease risks and vaccination benefits are needed.

RELEVANCE TO CLINICAL PRACTICE

Concerns about vaccine safety and efficacy including misinformation are important contributors to vaccine hesitancy. Addressing these factors, particularly among nurses who are considered trusted influencers of vaccination decisions in the community is an important strategy for pandemic preparedness.

Policy-Relevant Attitudes Toward COVID-19 Vaccination: Associations With Demography, Health Risk, and Social and Political Factors

Background: Vaccination is considered to be a key public health intervention to end the COVID-19 pandemic. Yet, the success of the intervention is contingent on attitudes toward vaccination and the design of vaccination policies. Methods: We conduct cross-sectional analyses of policy-relevant attitudes toward COVID-19 vaccination using survey data of a representative sample of Austrian residents collected by the Austrian Corona Panel Project (ACPP). As outcomes, we examine the individual readiness to get vaccinated, the support for compulsory vaccinations, and the preference for making the vaccine available free of charge. The independent variables include demographics, objective and perceived health risks, and social and political factors. Results: Although there is broad public support for making the vaccine available free of charge, vaccine hesitancy and the opposition to a vaccine mandate are widespread. The protective function of the vaccine for the individual only motivates limited support for vaccinations. Opposition to COVID-19 vaccination also stems from a lack of sense of community and an ongoing politicization of the issue through conspiracy theories and party politics. Conclusion: We propose that overcoming the inherent free-rider problem of achieving sufficiently high vaccination rates poses a potential dilemma for policymakers: Given the politicized nature of the issue, they may find themselves having to choose between making vaccinations compulsory at political costs and a lingering pandemic at high costs for public health and the economy. We propose that promoting a sense of community and addressing potential practical constraints will be key in designing an effective COVID-19 vaccination policy.

National retrospective cohort study to identify risk factors for in-hospital 30-day lethality in laboratory-confirmed cases of influenza

OBJECTIVE

To identify factors associated with the risk of death in adolescent and adult inpatients with laboratory-positive (reverse-transcription polymerase chain reaction) influenza in Mexico during consecutive influenza seasons (2018-2020).

PATIENTS AND METHODS

A retrospective cohort study used national surveillance system data, enrolling 3422 individuals. The association between various risk factors and 30-day in-hospital lethality were evaluated through risk ratios (RR) and 95% confidence intervals (CI).

RESULTS

The lethality rate was 18.1%. Flu vaccination history (RR = 0.56, 95% CI 0.42-0.78), early antiviral drug administration (≤ two days from symptom onset [reference ≥ 5 days], RR = 0.68, 95% CI 0.58-0.81), and a history of asthma (RR = 0.66, 95% CI 0.47-0.95) showed protective effects against influenza-attributable death. Mechanical ventilator support produced the highest increase in death risk (RR = 3.31, 95% CI 2.89-3.79). Male sex, older age, AH1N1 subtype, and other chronic diseases were also associated with fatal in-hospital influenza-related outcomes.

CONCLUSIONS

Our findings highlight the major relevance of promoting immunization in high-risk individuals, together with ensuring early and effective antiviral management in suspected influenza cases.

National retrospective cohort study to identify risk factors for in-hospital 30-day lethality in laboratory-confirmed cases of influenza

OBJECTIVE

To identify factors associated with the risk of death in adolescent and adult inpatients with laboratory-positive (reverse-transcription polymerase chain reaction) influenza in Mexico during consecutive influenza seasons (2018-2020).

METHODS

A retrospective cohort study used national surveillance system data, enrolling 3.422 individuals. The association between various risk factors and 30-day in-hospital lethality were evaluated through risk ratios (RRs) and 95% confidence intervals (CIs).

RESULTS

The lethality rate was 18.1%. Flu vaccination history (RR=0.56, 95% CI 0.42-0.78), early antiviral drug administration (≤2 days from symptom onset [reference ≥5 days], RR=0.68, 95% CI 0.58-0.81), and a history of asthma (RR=0.66, 95% CI 0.47-0.95) showed protective effects against influenza-attributable death. Mechanical ventilator support produced the highest increase in death risk (RR=3.31, 95% CI 2.89-3.79). Male sex, older age, AH1N1 subtype, and other chronic diseases were also associated with fatal in-hospital influenza-related outcomes.

CONCLUSIONS

Our findings highlight the major relevance of promoting immunization in high-risk individuals, together with ensuring early and effective antiviral management in suspected influenza cases.

Pneumococcal vaccine coverage among individuals aged 18 to 64 years old with underlying medical conditions in the UK: a retrospective database analysis

BACKGROUND

In the UK certain groups with pre-disposing conditions are eligible for vaccination with the pneumococcal polysaccharide vaccine (PPV23). Uptake of the vaccine in these individuals has not been reported for 10 years. Hence this study investigated the rates of pneumococcal vaccination, the time to vaccination since diagnosis, and factors associated with vaccination in individuals aged 18-64 years with certain underlying medical conditions.

METHODS

A retrospective database analysis was conducted using the Clinical Practice Research Datalink (CPRD). Individuals aged 18 to 64 years who had a diagnosis for underlying medical conditions of interest at the index date (January 1, 2011 to December 31, 2015) were included in this study. Both underlying conditions and pneumococcal vaccination were identified using Read codes. A multivariable logistic regression model was used to identify factors associated with pneumococcal vaccination.

RESULTS

A total of 99,153 individuals with underlying medical conditions were included in this study. Within 1 year of follow-up, 13.6% had received pneumococcal vaccination. This figure rose to 32.0% after 4 years of follow-up. The mean time between diagnosis and vaccination was 148.7 days across the overall cohort. Based on multivariate analysis of results, individuals with chronic heart disease, chronic kidney disease, chronic liver disease, chronic respiratory disease or diabetes mellitus were significantly less likely (P < 0.0001) to be vaccinated than those with immunosuppression. Individuals were significantly more likely to receive a pneumococcal vaccination if they received an influenza vaccination in the first year of follow-up than those who did not (P < 0.001).

CONCLUSIONS

Despite the Joint Committee on Vaccination and Immunisation (JCVI) recommendations for pneumococcal vaccination in clinical risk groups, rates of pneumococcal vaccination are suboptimal in the UK for individuals aged 18-64 with underlying medical conditions. Further emphasis should be made on the importance of increased pneumococcal vaccination coverage in the UK, given the increased risk of morbidity and mortality associated with indicative underlying medical conditions.

Public preference for COVID-19 vaccines in China: A discrete choice experiment

Background

As the coronavirus disease 2019 (COVID‐19) pandemic is sweeping across the globe, there is an urgent need to develop effective vaccines as the most powerful strategy to end the pandemic. This study aimed to examine how factors related to vaccine characteristics, their social normative influence and convenience of vaccination can affect the public's preference for the uptake of the COVID‐19 vaccine in China.

Methods

An online discrete choice experiment (DCE) survey was administered to a sample of China's general population. Participants were asked to make a series of hypothetical choices and estimate their preference for different attributes of the vaccine. A mixed logit regression model was used to analyse the DCE data. Willingness to pay for each attribute was also calculated.

Results

Data of 1236 participants who provided valid responses were included in the analysis. There was strong public preference for high effectiveness of the vaccine, followed by long protective duration, very few adverse events and being manufactured overseas. Price was the least important attribute affecting the public preference in selecting the COVID‐19 vaccine.

Conclusions

The strong public preferences detected in this study should be considered when developing COVID‐19 vaccination programme in China. The results provide useful information for policymakers to identify the individual and social values for a good vaccination strategy.

Patient or Public Contribution

The design of the experimental choices was fully based on interviews and focus group discussions participated by 26 Chinese people with diverse socio‐economic backgrounds. Without their participation, the study would not be possible.

The impact of sex and gender on immunotherapy outcomes

Immunotherapies are often used for the treatment, remission, and possible cure of autoimmune diseases, infectious diseases, and cancers. Empirical evidence illustrates that females and males differ in outcomes following the use of biologics for the treatment of autoimmune diseases, e.g., rheumatoid arthritis (RA), infectious diseases, e.g., influenza, and solid tumor cancers. Females tend to experience more adverse reactions than males following the use of a class of biologics referred to as immunotherapies. For immunotherapies aimed at stimulating an immune response, e.g., influenza vaccines, females develop greater responses and may experience greater efficacy than males. In contrast, for immunotherapies that repress an immune response, e.g., tumor necrosis factor (TNF) inhibitors for RA or checkpoint inhibitors for melanoma, the efficacy is reportedly greater for males than females. Despite these differences, discrepancies in reporting differences between females and males exist, with females have been historically excluded from biomedical and clinical studies. There is a critical need for research that addresses the biological (i.e., sex) as well as sociocultural (i.e., gender) causes of male-female disparities in immunotherapy responses, toxicities, and outcomes. One-size-fits-all approaches to immunotherapies will not work, and sex/gender may contribute to variable treatment success, including adherence, in clinical settings.

Variations of health check attendance in later life: results from a British birth cohort study

BACKGROUND

Older adults are advised to attend a number of preventive health checks to preserve health and identify risk factors for disease. Previous research has identified a number of health and social factors, labelled as predisposing, enabling and need factors, using Andersen's Behavioural Model of Health Service Use, that are associated with health care utilisation. We aimed to assess associations between factors from childhood and adulthood, and health check attendance in later life in a British birth cohort study.

METHODS

For 2370 study members from the MRC National Survey of Health and Development (NSHD), health check attendance was assessed at age 68. Study members were asked if they: attended blood pressure and cholesterol checks, had their eyes tested, received the influenza vaccine, attended colon cancer screening and dental checks. Health and social factors from childhood and adulthood were used in binomial regression models to test associations with health check attendance in men and women.

RESULTS

Health check attendance was high; 41% reported attending all six health checks within the recommended time frame. In multivariable models, being a non-smoker and having more health conditions in adulthood were associated with greater health check attendance in men and women. In women, childhood socioeconomic advantage, being more physically active in midlife and previously attending screening procedures, and in men, greater self-organisation in adolescence and being married were associated with attending more health checks in later life, following adjustments for childhood and adulthood factors.

CONCLUSIONS

A number of predisposing, enabling and need factors from childhood and adulthood were found to be associated with health check attendance at age 68, demonstrating the relevance of applying a life course perspective to Andersen's model in investigating health check attendance in later life. Health related factors were found to be stronger correlates of health check attendance than socioeconomic factors.

What isn't measured isn't done - eight years with no progress in Aboriginal and Torres Strait Islander adult influenza and pneumococcal vaccination

OBJECTIVES

To describe and compare vaccination coverage for Aboriginal and Torres Strait Islander (hereafter referred to as Indigenous) adults in 2004-05 and 2012-13, including the impact of national vaccination funding initiatives.

METHODS

National Aboriginal and Torres Strait Islander Health cross-sectional surveys - 2004-05 (n=5,757) and 2012-13 (n=5,482) - were compared. Self-reported influenza and pneumococcal vaccination coverage among Indigenous adults was analysed by age, remoteness, gender and risk factor status.

RESULTS

Influenza vaccination coverage among Indigenous adults in 2004-05 and 2012-13 remained low. While coverage increased for those aged 18-49 years from 23% to 29%, it declined for those aged ≥65 years from 84% to 74%. For remote areas, influenza coverage among those aged 50-64 years declined from 76% to 66%. Pneumococcal vaccination coverage remained very low and declined across all age groups in 2004-05 and 2012-13 (50-64 years: 30% to 23%). For remote areas, pneumococcal coverage declined among those aged 50-64 years from 52% to 32%.

CONCLUSIONS

Indigenous adult vaccination coverage for influenza and pneumococcal disease remains unacceptably low. Between 2004-05 and 2012-13, declines occurred in pneumococcal vaccination coverage across all age groups ≥18 years. Despite national funding of influenza vaccine in 2010, there was no increase in influenza coverage, except for the 18-49-year age group. Implications for public health: Current approaches to promote, deliver and monitor vaccination of Indigenous adults are inadequate.

The intersection of sex and gender in the treatment of influenza

Males/men and females/women differ in the outcome of influenza A virus (IAV) infections, vaccination, and antiviral treatments. Both sex (i.e. biological factors) and gender (i.e. sociocultural factors) can impact exposure and severity of IAV infections as well as responses and outcomes of treatments for IAV. Greater consideration of the combined effects of sex and gender in epidemiological, clinical, and animal studies of influenza pathogenesis is needed.

The Association between Smoking Status and Influenza Vaccination Coverage Rate in Korean Adults: Analysis of the 2010-2012 Korea National Health and Nutrition Examination Survey

Background

Globally, smoking is one of the biggest challenges in public health and is a known cause of several important diseases. Influenza is preventable via annual vaccination, which is the most effective and cost-beneficial method of prevention. However, subjects who smoke have some unhealthy behaviours such as alcohol, low physical activity, and low vaccination rate. In this study, we analyzed the relationship between smoking status and factors potentially related to the influenza vaccination coverage rate in the South Korean adult population.

Methods

The study included 13,565 participants aged >19 years, from 2010 to 2012 from the Korea National Health and Nutrition Examination Survey data. Univariate analyses were conducted to examine the association between influenza coverage rate and related factors. Multivariate analysis was obtained after adjusting for variables that were statistically significant.

Results

The overall vaccination rate was 27.3% (n=3,703). Older individuals (P<0.0001), women (P<0.0001), non-smokers (P<0.0001), light alcohol drinkers (P<0.0001), the unemployed (P<0.0001), and subjects with diabetes mellitus (P<0.0001), hypercholesterolemia (P<0.0001), and metabolic syndrome (P<0.0001) had higher influenza vaccination coverage than the others. In multivariate analyses, current smokers and heavy smokers showed lower vaccination rates (odds ratio, 0.734; 95% confidence interval, 0.63–0.854).

Conclusion

In the current study, smokers and individuals with inadequate health-promoting behaviors had lower vaccination rates than the others did.

Self-reported influenza vaccination rates and attitudes towards vaccination among health care workers: results of a survey in a German university hospital

OBJECTIVES

The objective of this survey was to analyse vaccination rates and attitudes towards vaccination among health care workers (HCWs). The period prevalence of self-reported acute respiratory infections in the influenza season 2014/2015 was examined.

STUDY DESIGN

A cross-sectional study was conducted among HCWs of a German university hospital using an anonymised questionnaire. Recruitment was performed by providing all medical and nursing staff a paper questionnaire with an invitation to participate.

METHODS

Descriptive aggregated data were generated from digitalised questionnaires for all variables. Differences in categorical variables were analysed by Chi-squared test. Textual data were analysed by an iterative process based on the grounded theory by Glaser and Strauss.

RESULTS

The response rate was 31% (677/2186). Probable influenza was described by 9% (64/677) of the participants. The overall self-reported vaccination rate was 55% (366/666). Self-reported vaccination rate was higher in physicians (172/239, 72%) than in nursing staff (188/418, 45%). HCWs in paediatrics (103/148, 70%) more likely received vaccines than HCWs in surgery (31/84, 37%). Most vaccinations were provided by medical staff on the wards (164/368, 45%). Self-reported lost work-time due to adverse events after vaccination was low (6/336, 2%). Eight categories for vaccine refusal were identified, whereof doubts about effectiveness and indication of the vaccine was most frequently mentioned (72/202, 36%).

CONCLUSIONS

Efforts to promote vaccination should focus on nursing staff and should provide scientific evidence on effectiveness, adverse effects, and the benefits of health care workers' vaccination for patients. Administering vaccines at the workplace proved to be a successful strategy in our setting. Studies are needed to assess the frequency of influenza causing disease in HCWs.

Benevolent personification of the MoH increases compliance with an emergency polio vaccination

OBJECTIVE

Parental compliance is crucial to the success of mass vaccination campaigns targeting children. Relying on psychological/neuroscientific research concerning the role of personification (i.e., viewing the inanimate as human) in behavior, the authors examined the effect of parents' personification of the Israeli Ministry of Health (MoH) on compliance with a publicly controversial mass vaccination campaign, which was aimed at stopping the spread of a wild poliovirus.

METHODS

Participants were 555 parents of children aged 9 or younger, residing in the center/north of Israel, an area covered by Phase 2 of the campaign. T1 assessment, employed two days prior to Phase 2, tapped into demographics, attitudes towards vaccination, intent to comply, and a benevolent personification of the MoH (i.e., "The MoH is caring") vs. a malevolent personification of the MoH ("The MoH is hysteric"). T2 assessment, transpiring four months after the end of the campaign, addressed presence and reasons for (non-)compliance.

RESULTS

The study's overall compliance rate was 61.8%. The principal reason for compliance was "adherence to the recommendations of the MoH" (68.49%). In a multivariate logistic regression analysis, prospective predictors of compliance were: an early intent to comply (O.R.=2.56, p=0.000), being male (O. R.=1.51, p=0.023), and a benevolent personification of the MoH (O.R.=1.21, p=0.019).

CONCLUSION

Parents who experienced the Israeli MoH as a benevolent protagonist were more likely to comply with the mass vaccination campaign. Findings highlight the role of leadership in public health campaigns during emergencies.

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.

Sex and Gender Impact Immune Responses to Vaccines Among the Elderly

In response to the recommended vaccines in older-aged individuals, sex differences occur in response to those that protect against influenza, tetanus, pertussis, shingles, and pneumococcal infections. The efficacy of vaccines recommended for older-aged adults is consistently greater for females than for males. Gender differences as well as biological sex differences can influence vaccine uptake, responses, and outcome in older-aged individuals, which should influence guidelines, formulations, and dosage recommendations for vaccines in the elderly.

Barriers to influenza vaccine uptake in obese people in Italy: Changes 2005-2013

BACKGROUND

Obesity is an independent risk factor for developing flu-related complications.

OBJECTIVE

The aim of this study was to analyze influenza vaccine uptake (VU) in the Italian obese, before and after the introduction of obesity among the national recommendations, and to evaluate factors associated to VU.

METHODS

The comparison of two editions of the national survey carried out in 2004-2005, before the inclusion of obese people among the specific high risk categories for flu complications, and in 2013, reaching a sample of 21,857 persons who declared to have a BMI>30. Multilevel logistic regression was used to evaluate potential independent predictors of influenza immunization.

RESULTS

Influenza vaccination coverage was 27.16% in 2013, versus 31.61% in 2005. A significant reduction of VU was registered after the introduction of obesity among the high risk conditions, for which flu VU was recommended. Regression modeling, both in adults and in older people, confirmed that barriers to VU in 2013 were younger age, medium level of education, absence of chronic disease, smoking habit, and reporting no contacts with GPs during the previous 12months. Among those aged 65 or more, the role of regional policies was associated to VU.

CONCLUSIONS

Immunization rates among young obese population are low, especially if not affected by comorbidities. Moreover, a reduction was registered in 2013 with respect to 2005. Flu vaccine uptake among the older population seems to be influenced by regional vaccination strategies. The development of novel strategy is warranted, especially among the young adults.

Predictors of influenza vaccine uptake during the 2009/10 influenza A H1N1v ('swine flu') pandemic: Results from five national surveys in the United Kingdom

OBJECTIVES

To investigate reasons underlying the low uptake of the influenza A H1N1v vaccination in the UK during the 2009/10 pandemic.

METHODS

We analysed data from five national telephone surveys conducted in the UK during the latter stages of the pandemic to identify predictors of uptake amongst members of the public offered the vaccine by their primary care physician (n=1320). In addition to demographic variables, participants reported: reasons for declining the vaccination, levels of worry about the risk of catching swine flu, whether too much fuss was being made about the pandemic, whether they or a close friend or relative had had swine flu, how effective they felt the vaccine was, whether they had previously had a seasonal flu vaccination, how well prepared they felt the government was for a pandemic and how satisfied they were with information available about the pandemic. Most participants (n=734, 55.6%) reported being vaccinated against swine flu, compared to 396 who had not been vaccinated and were unlikely to be vaccinated in the future.

RESULTS

The main reasons given for declining vaccination were concerns over the vaccine's safety, and being generally healthy. Controlling for demographic variables, risk factors for not being vaccinated were: being female, not having a long-standing infirmity or illness, not having been vaccinated against seasonal flu in previous years, feeling that too much fuss had been made about the pandemic and believing that the vaccine was ineffective.

CONCLUSIONS

Interventions that target these factors may be effective in improving uptake in a future pandemic.

Sex-based differences in immune function and responses to vaccination

Females typically develop higher antibody responses and experience more adverse reactions following vaccination than males. These differences are observed in response to diverse vaccines, including the bacillus Calmette-Guerin vaccine, the measles, mumps and rubella vaccine, the yellow fever virus vaccine and influenza vaccines. Sex differences in the responses to vaccines are observed across diverse age groups, ranging from infants to aged individuals. Biological as well as behavioral differences between the sexes are likely to contribute to differences in the outcome of vaccination between the sexes. Immunological, hormonal, genetic and microbiota differences between males and females may also affect the outcome of vaccination. Identifying ways to reduce adverse reactions in females and increase immune responses in males will be necessary to adequately protect both sexes against infectious diseases.

Sex-based biology and the rational design of influenza vaccination strategies

Biological (ie, sex) differences as well as cultural (ie, gender) norms influence the acceptance and efficacy of vaccines for males and females. These differences are often overlooked in the design and implementation of vaccination strategies. Using seasonal and pandemic influenza vaccines, we document profound differences between the sexes in the acceptance, correlates of protection, and adverse reactions following vaccination in both young and older adults. Females develop higher antibody responses, experience more adverse reactions to influenza vaccines, and show greater vaccine efficacy than males. Despite greater vaccine efficacy in females, both young and older females are often less likely to accept influenza vaccines than their male counterparts. Identification of the biological mechanisms, including the hormones and genes, that underlie differential responses to vaccination is necessary. We propose that vaccines should be matched to an individual's biological sex, which could involve systematically tailoring diverse types of FDA-approved influenza vaccines separately for males and females. One goal for vaccines designed to protect against influenza and even other infectious diseases should be to increase the correlates of protection in males and reduce adverse reactions in females in an effort to increase acceptance and vaccine-induced protection in both sexes.

Influenza vaccination coverage rates among diabetes sufferers, predictors of adherence and time trends from 2003 to 2010 in Spain

A descriptive cross-sectional study was conducted for adults (aged ≥ 50 y) with diabetes. Data was obtained from the 2009 European Health Interview Survey for Spain and the 2003 and 2006 Spanish National Health Surveys. To assess influenza vaccination status, we considered the response (yes or no) to the question "Have you received the influenza vaccine in the previous season?" Both dependent and independent variables were based on the survey questionnaires. The independent variables analyzed included socio-demographic characteristics, health-related variables and use of health care services. The coverage among adults with diabetes in 2010 was 65.0% (95% CI: 62.1-67.7) compared with 41.2% (95% CI 40.0-42.4) for those without diabetes (p<0.01) adjusted OR 1.67 (95% CI: 1.40-1.99). The positive predictors of vaccine uptake among diabetic adults were: higher age, being male, the presence of associated chronic conditions and physician visits in the last 2 wk. The vaccine uptake among adults with diabetes was 61.4% (95% CI: 57.9-64.8) in 2003 and 63.8% (95% CI: 60.7-66.8) in 2006.The adjusted OR of having been vaccinated in 2010 with respect to 2003 was not significant 1.18 (95% CI: 0.97-1.44). We conclude that the levels of influenza vaccination coverage are below desirable levels among adults with diabetes. Furthermore, trend analysis in influenza vaccination coverage indicates that influenza vaccination rates in adults with diabetes have not improved in recent years. Urgent strategies for increasing vaccination coverage among diabetes sufferers are necessary especially for those aged 50-59, women, those without chronic conditions and those who are not frequent users of health care services.

Factors associated with uptake of seasonal and pandemic influenza vaccine among clinical risk groups in the UK: an analysis using the General Practice Research Database

BACKGROUND

Influenza vaccine uptake rates are low compared with uptake rates of many other vaccines. It is unclear how this differs between risk groups in the population and between pandemic and non-pandemic influenza vaccines.

AIM

This study sought to estimate uptake rates of pandemic and seasonal influenza vaccines among clinical risk groups in the UK during the 2009/2010 influenza season and to identify predictors of vaccine uptake in this cohort.

METHODS

Uptake rates were calculated using data from the UK General Practice Research Database (GPRD). Predictors of vaccination were identified using a modified Poisson regression with robust standard error estimates.

RESULTS

Uptake of pandemic influenza vaccine in clinical risk groups was 40.3% and uptake of seasonal influenza vaccine was 61.3%. Factors found to be predictive of seasonal and pandemic influenza vaccination included age and the total number of underlying health conditions an individual had. At risk individuals in those age groups in which universal vaccination of the general population was recommended were more likely to have been vaccinated than individuals in age groups in which only clinical risk groups were recommended for vaccination; hence children in clinical risk groups were more likely to receive pandemic than seasonal influenza vaccine. In older people, having a history of Guillain Barré syndrome was associated with a reduced likelihood of receipt of both seasonal (IRR(adj) 0.83, CI(95) 0.77-0.90) and pandemic influenza vaccines (IRR(adj) 0.82, CI(95) 0.73-0.92).

DISCUSSION

Uptake of pandemic influenza vaccine was lower than that of seasonal influenza vaccine among those at a clinically high risk of influenza related morbidity. This suggests that vaccination strategies may need to be altered during future pandemics. Recommending universal vaccination within age categories in which there is a large proportion of high risk individuals could be considered as this may result in higher uptake among clinical risk groups.

Vaccine history, gender and influenza vaccination in a household context

BACKGROUND

Few studies have investigated the effect of the history of vaccination on the current influenza vaccine uptake. The objective of this paper is to study the effects of vaccine history, for each sex separately, on the likelihood of vaccine uptake among single-head households and two-person households, controlling not only for the respondents' own prior vaccination history but also the history of vaccination among possible co-residents.

MATERIALS AND METHODS

We used logistic regression and data from a nationally representative telephone survey of the non-institutionalized Norwegian population aged ≥ 65 years to estimate our models (N=354). The survey was carried out in November 2008.

RESULTS

The lowest vaccine uptake was found among those who live alone with no prior history of vaccination and among those who live in two-person households where both members had no prior history of vaccination (10-22%). Those who live in two-person households where both members had previously been vaccinated had the highest vaccine uptake (86%). While a man who has previously been vaccinated has a higher likelihood of continued vaccination if his wife also has a prior history of vaccination, a woman with a prior history of vaccination is not dependent on her husband's prior practice with respect to the probability of continued vaccination. Of those who have no history of vaccination, more women than men are vaccinated for the first time when they have a spouse who has a history of vaccination.

CONCLUSION

Our study shows that the history of vaccination of a co-resident/spouse has an effect above and beyond the respondent's own vaccination history. The results indicate that there are gender differences in the willingness to encourage family members to be vaccinated or to embark upon a familial vaccination regime in order to protect the individual's own personal health and that of other family members from influenza. To the best of our knowledge such gender differences have never been shown before in research on influenza vaccine uptake. However, the finding is in accordance with a number of studies on the role of gender and the positive effect on health and mortality of social support and social control in marriage.

Coverage and predictors of vaccination against 2009 pandemic H1N1 influenza in Madrid, Spain

This study aimed to ascertain the coverage of vaccination against pandemic influenza in individuals aged over 6 months for whom vaccination is indicated due to a chronic health condition using as data source clinical information recorded in the primary care clinical history. Of all those for whom vaccination was indicated (1,114,632), 14.6% (162,616) finally received the vaccine. There were statistically significance differences in coverage for sex (16.5% for men and 13.1% for women), age groups (5% for people under 30 years and 20% for those over 60), number of chronic conditions (11.1% for one condition, 22.5% for two conditions, and 31.3% for three or more conditions) and depending on the chronic health condition considered. The probability of being vaccinated increased with male sex, age, number of indications, type of medical card (lower among no income) and having been vaccinated against 2009 season influenza. We concluded that the coverage finally reached for those people with an indication due to chronic health condition in the H1N1 campaign was much lower than expected and wished. It is essential to investigate the different factors that could have intervened in the behavior of the population so that more efficient approaches can be adopted in future influenza pandemics.