Gender influence in influenza vaccine uptake in Spain: Time trends analysis (1995–2006)

This study aims to analyze gender differences in influenza vaccine coverage and predictors of vaccine uptake in Spain from year 1995 to 2006.     

Vaccination against 2008/2009 and 2009/2010 seasonal influenza in Spain: coverage among high risk subjects, HCWs, immigrants and time trends from the 2005/2006 campaign

Influenza continues to be a very important cause of morbidity, mortality and a large number of hospitalizations each year, however the compliance with vaccine uptake is low and has barely varied over time among health care workers (HCWs) and people under 65 years of age suffering a chronic condition. Based on data from two nation-wide representative health surveys namely the 2006 Spanish National Health Survey and the 2009 European Health Interview Survey for Spain the aim of this study is to describe influenza vaccination coverage and time trends for the Spanish population as a whole and in recommended populations in four vaccination campaigns: 2005/2006, 2006/2007, 2008/2009 and 2009/2010.Our results show an increasing trend (OR 1.03) in seasonal influenza vaccine coverage for the total population from 2005/2006 to 2009/2010, especially in HCWs (21.8% in 2005/2006; 31.1% in 2009/2010). Coverage in people under 60 with a chronic disease remains low and did not vary significantly during the analyzed period. Immigrants presented a significantly lower probability of having received the influenza vaccine than indigenous people in the 2008/2009 campaign.Different strategies need to be implemented in order to achieve higher coverage levels in these at-risk populations.     

Negative trends from 2008/9 to 2011/12 seasons in influenza vaccination coverages among high risk subjects and health care workers in Spain

Objectives

We aim to describe influenza vaccination coverage for the Spanish population across four consecutive campaigns (2008/2009 to 2011/2012). The data was analyzed by high risk groups and health care workers (HCWs). Also, coverage trends were analyzed to assess uptake in post-pandemic seasons.

Methods

We used data from two nation-wide representative health surveys namely the 2009/10 European Health Interview Survey for Spain (N = 22,188) and the 2011–12 Spanish National Health Survey (N = 21,007) Influenza vaccination status was self-reported. We analyzed influenza vaccine coverage by age, sex, number of chronic conditions, being a heath care worker (HCWs) and nationality. Time trends for campaigns among high risk groups were estimated by a multivariate logistic regression model.

Results

We analyzed data from 43,072 subjects aged ≥16 years. As a whole, coverage decreased by 3.31% (22.57–19.26%) between the 2008/2009 and 2011/2012 campaigns with a significant decreasing trend (OR 0.92; 95% CI: 0.90–0.94).Coverage in people under 60 years with a chronic disease decreased significantly (OR 0.92: 95% CI: 0.85–0.99) during the analyzed period from 21.02% in 2008/2009 to 17.40% in 2011/2012. Among HCWs, the highest influenza vaccination coverage was achieved in 2009/2010 (31.08%) in the latest campaign coverage has almost halved (17.88%). For the 2011/2012 season and for all age groups the variables associated with a higher probability of having received the influenza vaccine were older age and presence of associated chronic conditions. Among those aged ≥60 years, immigrants had lower uptake (OR 0.60; 95% CI: 0.32–0.99).

Conclusions

Seasonal influenza vaccine uptake rates in the recommended target groups in Spain are unacceptably low and seem to be decreasing in the post pandemic seasons. Further studies are necessary to precisely identify reasons for non-compliance and barriers to influenza vaccination. Meanwhile urgent strategies to improve seasonal vaccination uptake must be discussed and implemented.     

Comparison of influenza vaccination coverage between immigrant and Australian-born adults

Australia has a large immigrant population but there are few data regarding whether influenza vaccine coverage in adults varies according to country of birth. We quantified and compared self-reported influenza vaccination coverage between Australian-born and immigrant residents aged ⩾49 years enrolled in a large cohort (the 45 and Up Study), surveyed in 2012 and 2013. Estimated vaccine coverage was adjusted for age, sex and other factors known to be associated with vaccine uptake. Among 76,040 participants included in the analyses (mean age 66.2 years), 21.6% were immigrants. In Australian-born adults aged 49–64 and 65+ years the age- and sex-adjusted estimates for influenza vaccination within the year prior to survey was 39.5% (95% CI 38.9–40.0) and 70.9% (70.4–71.5) respectively. The corresponding estimates in immigrants were significantly lower at 34.8% (33.7–35.8) and 64.4% (63.4–65.4) respectively. Among immigrants, coverage varied by region of birth, and was slightly lower among those who spoke a language other than English at home compared to those who only spoke English. Among immigrants there was no significant difference in coverage comparing those who migrated when they were children to those who migrated as adults and coverage did not differ significantly according to years lived in Australia. Programs to increase adult vaccination coverage should consider the needs of immigrants.     

Interventions to increase the uptake of seasonal influenza vaccination among pregnant women: A systematic review

BackgroundPregnant women and their infants under 6 months of age infected with influenza have a high risk of serious morbidity and mortality. Influenza vaccine during pregnancy offers 3-for-1 benefits to pregnant women, fetuses and newborn infants. Current vaccination uptake rates during pregnancy, however, are often lower than other high-risk groups and the general population.MethodsWe systematically reviewed evidence on the effectiveness of interventions to improve influenza vaccination coverage in pregnant women. Risk differences (RDs) were calculated from the included studies.ResultsEleven studies were included in the review, of which four were randomized controlled trials (RCTs). Three cohort studies assessed provider-focused interventions while four RCTs and one cohort study evaluated pregnant women-focused interventions. Two cohort studies and a prospective intervention study assessed the effectiveness of bundled interventions. No study solely assessed the effectiveness of interventions to enhance access to influenza vaccination. One moderate quality RCT showed that an influenza pamphlet, with or without a verbalized benefit statement, improved the vaccination rate (RD = 0.26; RD = 0.39). The other reviewed RCTs showed discordant results, with RDs ranging from −0.15 to 0.03. Although all observational studies significantly improved vaccination rates (RDs ranged from 0.03 to 0.44), the quality of the evidence varied.ConclusionsThere is a lack of effective interventions to increase the influenza vaccination rate in pregnant women. Based on the existing research, we recommend that clinicians provide influenza pamphlets to pregnant women with a verbalized statement about the benefits of influenza vaccine to newborns. Further high-quality RCTs are needed to develop successful maternal influenza vaccination programs. Increased clarity in reporting the content of interventions would help to improve the comparability and generalizability of the published studies.     

Varicella vaccination coverage inverse correlation with varicella hospitalizations in Spain

Varicella vaccines available in Spain were marketed in 1998 and 2003 for non-routine use. Since 2006 some regions included universal varicella vaccination in their regional routine vaccination programs at 15–18 months of age. Regions without universal vaccination in toddlers, but instead with the strategy of vaccinating susceptible adolescents, reached different varicella vaccination coverage through private market.This study shows the correlation between severe varicella zoster virus infections requiring hospitalization and the varicella vaccination coverage by region.A total of 3009 hospital discharges related to varicella were reported in 2009–2010. The overall annual rate of hospitalization was 3.27 cases per 100,000. In children younger than 5 years old varicella hospitalization rate was 30.73 cases per 100,000.Varicella related hospitalizations were significantly lower in the regions with universal vaccination. In those regions without universal vaccination at 15–18 months of age, those with higher coverage in private market showed lower hospitalization rates.     

Determinants of influenza vaccination coverage rates among primary care patients in Krakow,Poland and the surrounding region

ObjectivePoland is significantly behind other European countries in terms of influenza vaccination coverage. In addition, the vaccination rate among health care personnel in Poland is also very low. The aim of this study was to determine the current barriers to achieving effective influenza vaccination coverage among primary health care (PHC) patients and physicians in Poland and to reveal any associations between the patients’ and physicians’ characteristics and the influenza vaccination coverage rate among patients.MethodA cross-sectional questionnaire-based survey was distributed among 18 PHC physicians and 533 their patients in Krakow, Poland and the surrounding region. The data from patients were associated with the doctors’ characteristics.ResultsThe reasons for not receiving the influenza vaccine differed between patients and their physicians. Among the patient population, the main reason behind vaccination non-compliance was the self-perception of good health, while forgetting about the vaccination was the main reason among the physicians.The factors that had the positive influence on the patients’ decision to receive the vaccination involved: older age, being a widower, being retired, having a chronic disease, being vaccinated against influenza in the past and awareness of influenza complications. Moreover, those patients who had received sufficient influenza vaccination education from their healthcare provider and had been the patients of physicians who had been vaccinated against influenza, had significantly higher vaccination rates.ConclusionImproved patients and doctors education strategies are needed to maximize influenza vaccination coverage rates. Information regarding the need and benefits of the influenza vaccine, along with details on where and when to receive vaccination will provide a positive influence on a patients’ decision-making process regarding vaccination compliance. Also, the free of charge influenza vaccinations for all primary health care workers should be considered.     

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.     

Motivating factors for high rates of influenza vaccination among healthcare workers

Background

Recent guidance from related regulatory agencies and medical societies supports mandatory vaccination of healthcare workers (HCW) against influenza. At St. Jude Children's Research Hospital, a pediatric oncology referral center, more than 90% of HCWs receive vaccine each year without a policy mandating immunization. Factors associated with HCW uptake of influenza vaccines have not previously been evaluated in a high compliance rate setting.

Methods

A structured, anonymous, electronic questionnaire was distributed in August 2010 to employees (HCW and non-HCW). Demographics, prior receipt of influenza vaccines, reasons for acceptance or refusal of seasonal and 2009 H1N1 pandemic vaccine, and attitudes on mandatory vaccination were assessed.

Results

95.0% of 925 HCWs and 63.1% of all 3227 qualifying employees responded to the survey. 93.8% and 75.2% of HCW reported receiving seasonal and 2009 H1N1 influenza vaccines, respectively, in the 2009-2010 season. Benefits to self and/or patients were cited as the most frequent reasons for accepting seasonal (83.5% and 78.3%, respectively) and 2009 H1N1 (85.9% and 81.1%, respectively) vaccination. 36.6% of HCWs opposed mandating influenza vaccination; 88.2% and 59.9% of whom reported receiving the seasonal and 2009 H1N1 influenza vaccines, respectively. Violation of freedom of choice and personal autonomy were the most frequently reported reasons for opposition.

Conclusion

In this cohort of HCWs with a high influenza vaccination rate, realistic assessments of the potential benefits of vaccination appear to have driven the choice to accept immunization. Despite this, mandating vaccination was viewed unfavorably by a significant minority of vaccinated individuals. Employee concerns over autonomy should be addressed as institutions transition to mandatory vaccination policies.     

Effectiveness of the influenza vaccination program for the elderly in Taiwan

Background and objectives

Since 1998, an influenza vaccination program has been implemented by the Taiwan government targeting people aged ≥65 years. However, the evidence of the effectiveness of this program in preventing influenza, which is based on the nation-wide database, is lacking. This study attempted to estimate the effectiveness of the influenza vaccination program in preventing influenza- and pneumonia-associated outpatient visits and hospitalization in the elderly.

Methods

Randomly sampled data of 1 million claims from the National Health Insurance Research Database compiled into seven consecutive cohorts were used to perform this analysis. Elderly claimants aged ≥65 years were included in each cohort. To decrease potential bias between vaccinated and unvaccinated subjects, the propensity score method was applied. Logistic regression and zero-inflated negative binominal regression were used to examine the effectiveness of vaccination in preventing influenza- and pneumonia-associated outpatient visits and hospitalization.

Results

A significant decrease in both the risk and frequency of hospitalization was observed in elderly people who received influenza vaccination compared with those who did not. No similar decrease was observed in the risk and frequency of outpatient visits for influenza and pneumonia.

Conclusion

Vaccination against influenza reduced hospitalization for influenza and pneumonia in elderly Taiwanese people. These results are meaningful for the promotion of vaccination policy. Annual influenza vaccination of the elderly should be encouraged.     

Comparison of self-report influenza vaccination coverage with data from a population based computerized vaccination registry and factors associated with discordance

Objectives

We aim to compare influenza vaccination coverages obtained using two different methods; a population based computerized vaccination registry and self-reported influenza vaccination status as captured by a population survey.

Methods

The study was conducted in the Autonomous Community of Madrid (ACM), Spain, and refers to the 2011/12 influenza vaccination campaign.Information on influenza vaccination status according to a computerized registry was extracted from the SISPAL database and crossed with the electronic clinical records in primary care (ECRPC). Self-reported vaccine uptake was obtained from subjects living in the ACM included in the 2011–12 Spanish National Health Survey (SNHS). Independent study variables included: age, sex, immigrant status and the presence of high risk chronic conditions. Vaccination coverages were calculated according to study variables. Crude and adjusted prevalence ratios were computed to assess concordance.

Results

The study population included 5,245,238 adults living in the ACM in year 2011 with an individual ECRPC and 1449 adult living the ACM and interviewed in the SNHS from October 2011 to June 2012.The weighted vaccination coverage for the study population according to self-reported data was 19.77% and 15.04% from computerized registries resulting in a crude prevalence ratio (cPR) of 1.31 (95% CI 1.20–1.44) so self-reported data significantly overestimated 31% the registry coverage. Self-reported coverages are always higher than registry based coverages when the study population is stratified by the study variables. Self-reported overestimation was higher among men than women, younger age groups, immigrants and those without chronic conditions. Both methods provide the most concordant estimations for the target population of the influenza vaccine.

Conclusions

Self-report influenza vaccination uptake overestimates vaccination registries coverages. The validity of self-report seems to be negatively affected by socio-demographic variables and the absence of chronic conditions. Possible strategies must be considered and implemented to improve both coverage estimation methods.     

External cues to action and influenza vaccination among post-graduate trainee physicians in Toronto,Canada

Background

Understanding factors affecting trainee physician choices about vaccination may permit the design of more effective vaccination programmes.

Methods

To identify factors associated with seasonal and pandemic influenza vaccination, an online questionnaire based on the health belief model was sent to trainee physicians registered at the post-graduate medical education office at the University of Toronto in September 2011.

Results

963 complete responses were received from 1884 trainee physicians (51%); 28 (2.9%) reported an allergy to vaccine components and were excluded from further analysis. Reported seasonal influenza vaccination rates in 2008, 2009 and 2010 were 69% (648/935), 75% (708/935) and 76% (703/935), respectively; 788 (84%) reported receiving the A(H1N1)pdm09 vaccine. In multivariable analysis, number of years of post-graduate training (OR for 4+ versus 1–3 post-graduate years 2.2 (95% CL 1.3, 3.8)) was associated with receipt of the 2009 pandemic vaccine, as were four components of the health belief model: odds ratios were 4.7 (95% CL 3.0, 7.5) for perceived severity, 1.9 (95% CL 1.2, 2.9) for perceived benefits, .35 (95% CL .21, .59) for perceived barriers, and 5.8 (95% CLI 3.6, 9.1) for external cues to action. Both vaccinated and unvaccinated respondents reported that their decisions were significantly influenced by encouragement from their colleagues, families and employers.

Conclusion

Self-reported vaccination coverage among trainee physicians was high. External cues to action appear to be particularly important in trainee physician vaccination decisions: active institutional promotion may increase influenza vaccination rates in trainees.     

北京市2008—2010年老年人流行性感冒疫苗接种情况及影响因素分析

流行性感冒(流感)已经多次引起世界范围大流行.2009年王小莉等[1]用蒙特卡罗模型对北京市甲型H1N1流感感染人数进行了估算,约有180万人感染.接种疫苗仍是预防流感最经济有效的措施[2].本研究对北京市老年人在2008-2010年流感流行前后流感疫苗接种的情况及影响2010年接种流感疫苗的因素进行了调查.     

Effectiveness of influenza vaccination in elderly diabetic patients: A retrospective cohort study

Purpose

Studies regarding the clinical benefits of influenza vaccination in diabetic patients are limited. This study evaluated if the elderly diabetic patients who have had influenza vaccination would have benefits such as reduced medical care and mortality.

Methods

We used the universal insurance claims data from 2001 to 2009 in Taiwan to identify annual elderly patients with diabetes cohorts with (N = 4454) and without (N = 4571) influenza vaccination. The risk of developing pneumonia or influenza, respiratory failure, intensive care, hospitalization, and mortality were measured and compared between cohorts within one year of follow-up.

Results

The vaccine cohort had lower incidences of pneumonia or influenza and respiratory failure compared with the non-vaccine cohort. More importantly, the vaccine cohort had a hospitalization rate that was 11% less than the non-vaccine cohort (29.6 vs. 33.1 per 100 person-years) with an adjusted hazard ratio (HR) of 0.88 (95% CI 0.81–0.96). The vaccine cohort was also less likely to be admitted to the intensive care unit (ICU) [0.58 vs. 2.05 per 100 person-year; adjusted HR 0.30 (95% CI 0.19–0.47)] and less likely to expire [3.13 vs. 7.96 per 100 person-year; adjusted HR 0.44 (95% CI 0.36–0.54)]. Influenza vaccination reduced the hospitalization cost by 1282.6 USD, compared with patients without influenza vaccination (95% CI −2210.3, −354.8).

Conclusion

Influenza vaccination is associated with a reduced risk of morbidity, hospitalization, ICU admissions, and mortality. In addition, the hospitalization cost is reduced.     

Human papillomavirus vaccination coverage among Greek higher education female students and predictors of vaccine uptake

One of the biggest public health measures to prevent HPV infection, and consequently, cervical cancer, is the HPV vaccine. Greece introduced HPV vaccines to its National Vaccination Program in 2008.     

Impact of prior seasonal influenza vaccination and infection on pandemic A (H1N1) influenza virus replication in ferrets

Early epidemiologic and serologic studies have suggested pre-existing immunity to the pandemic A (H1N1) 2009 influenza virus (H1N1pdm) may be altering its morbidity and mortality in humans. To determine the role that contemporary seasonal H1N1 virus infection or trivalent inactivated vaccine (TIV) might be playing in this immunity we conducted a vaccination-challenge study in ferrets. Vaccination with TIV was unable to alter subsequent morbidity or contact transmission in ferrets following challenge with H1N1pdm. Conversely, prior infection with the contemporary seasonal H1N1 strain altered morbidity, but not transmission, of H1N1pdm despite the detection of only minimal levels of cross reactive antibodies.     

Veteran influenza vaccination acceptance rates after completion of the COVID-19 vaccination series among historical influenza vaccine refusers

BackgroundVaccine hesitancy remains an obstacle in disease prevention. The recent COVID-19 pandemic highlighted this issue and may influence acceptance of other recommended immunizations. The objective of this study was to determine the association between receiving the COVID-19 vaccination and the subsequent acceptance of the influenza vaccination in a Veteran population that historically declined influenza vaccination.MethodsInfluenza vaccination acceptance rates for the 2021–2022 influenza season were compared in patients who historically declined the influenza vaccine and either received or declined COVID-19 vaccinations. Logistic regression analysis was used to analyze factors associated with receiving influenza vaccination among vaccine hesitant individuals.ResultsA higher proportion of patients who had received the COVID-19 vaccination(s) subsequently accepted the influenza vaccination compared to the control group (37% vs. 11%, OR = 5.03; CI 3.15–8.26; p = 0.0001).ConclusionAmong previous influenza vaccine decliners, those who received COVID-19 vaccination had significantly higher odds of receiving subsequent influenza vaccination.     

Vaccination coverage against 2009 seasonal influenza in chronically ill children and adults: Analysis of population registries in primary care in Madrid (Spain)

Using electronic clinical records in primary care (ECRPC) of the entire population living in the Autonomous Community of Madrid, Spain (5,102,568 persons) as a data source, this study aimed to ascertain seasonal anti-influenza vaccination coverage in the chronically ill at-risk children (aged 6 months to14 years) and adults (15–59 years).     

Intention to receive influenza vaccination prior to the summer influenza season in adults of Hong Kong, 2015

Following a severe winter epidemic of drifted influenza A(H3N2) during January–March 2015, the Hong Kong government purchased vaccines of southern hemisphere formulation for administration prior to the anticipated summer influenza epidemic. This is the first time that seasonal influenza vaccines will be delivered twice within the same year in Hong Kong. We conducted a household telephone survey to investigate the acceptance of Hong Kong adults to pre-summer influenza vaccination. We found that the proportion of people reporting intention to receive vaccination was 37.8, 24.0, 31.4, and 34.4% in the age groups of 18–39, 40–59, 60–69, and 70 years or above. Only 31.3% of respondents who claimed they were parents or guardians said they would take their children to receive vaccination if the new vaccine was available. These findings suggested that intention to receive pre-summer vaccination was low even among the priority group of older people.     

Variability in influenza vaccination opportunities and coverage among privately insured children

BackgroundUniversal influenza vaccination has been recommended since 2010, yet influenza vaccination rates among children aged 6 months to 17 years remain low compared with other routinely recommended childhood vaccines.ObjectiveAssess in-plan vaccination coverage, opportunities, and missed opportunities during the 2016–2017 influenza season.Study Design:Retrospective analyses using 2016–2017 MarketScan® data for 2,768,799 privately insured children aged 1–17 years by the end of 2016 who were continuously enrolled in the same insurance plan during the 2016–2017 influenza season (defined as August 1, 2016 through May 31, 2017). We assessed in-plan vaccination coverage (percentage receiving ≥ 1 dose of influenza vaccine from August 2016-May 2017) and vaccination opportunities (percentage with ≥ 1 provider visit between September 2016 – May 2017). Among children who remained unvaccinated at the end of the season, those with ≥ 1 influenza vaccination opportunity between September 2016-May 2017 were determined to have a missed opportunity.ResultsIn-plan vaccination coverage during the 2016–17 season was 67.7% in infants (born 2015), 49.5% in toddlers (born 2012–2014), 35.0% in school-aged children (born 2004–2011), and 22.3% in teenagers (born 1999–2003). Like vaccination coverage, vaccination opportunities decreased with age (infants: 97.7%, toddlers: 91.9%, school-aged children: 82.6%, teenagers: 79.3%). Among unvaccinated children, 93.1%, 84.1%, 73.6% and 73.6% of each age group had a missed opportunity for influenza vaccination.ConclusionOpportunities for and coverage with influenza vaccination vary even among privately insured children. Along with continued efforts to reduce missed opportunities, effective strategies to bring children to their doctor for annual influenza vaccination are needed, particularly for older children.