Coverage rates of influenza vaccination in France: a population-based cross-sectional analysis of seasons 2001-2002 and 2002-2003

INTRODUCTION: Influenza is a serious health problem in Europe. Vaccination is the only preventive measure, reducing mortality and morbidity of influenza in all age groups. OBJECTIVES: The authors had for aim to assess influenza vaccination coverage during two seasons in France, to understand the incentives and barriers to vaccination and to determine vaccination intentions for the following winter. METHODS: A random-sampling, mail-based household survey was made among non-institutionalised individuals aged 15 and over. The surveys for 2001-2002 and 2002-2003 used the same questionnaire and were subsequently pooled. Three target groups were determined for analysis: (1) persons aged 65 and over; (2) people working in the medical field and (3) persons aged 65 and over or working in the medical field. RESULTS: Influenza vaccination coverage in France decreased from 23.0% in 2001-2002 to 22.4% in 2002-2003. Most frequent reasons for being vaccinated were advice from the family doctor (50.8%), influenza considered as a serious illness (45.3%) and free vaccine (44.1%). Reasons for not being vaccinated mentioned by people who had never been vaccinated were young age (27.0%), not considering vaccination (18.9%), and not expecting to catch influenza (13.9%). CONCLUSION: Vaccination coverage decreased during the 2002-2003 season in comparison to the 2001-2002 season. The family doctor is the most important source of encouragement for people to be vaccinated against influenza. We therefore suggest that family doctors be better informed on influenza vaccine and the disease itself, so that they can actively inform their patients on these topics.     

Developments in influenza vaccination coverage in England, Scotland and Wales covering five consecutive seasons from 2001 to 2006

This study aims at assessing trends in influenza vaccination coverage from 2001 to 2006 in Great Britain, at understanding drivers and barriers to vaccination and at identifying vaccination intentions for influenza season 2006/2007. In seasons 2001/2002 to 2005/2006, telephone-based household surveys representative of the population from age 16 were conducted, with about 2000 interviews per season (10,095 in total). Overall influenza vaccination coverage rate in Great Britain reached 25.9% in season 2005/2006. A sub-analysis showed that the highest coverage was reported in Wales reaching 33.3%. In the elderly recommended vaccination (from age 65), the coverage reached 79% in 2005/2006. Advice from the family doctor and the perception that influenza is a serious illness were the most frequent reasons for getting vaccinated. The most frequent reasons for not getting vaccinated, in persons never vaccinated before, were that they had not considered immunisation or had not received a recommendation from their family doctor. Those vaccinated in the past but not in the current season said they had not thought about vaccination/forgot. A gap continues to exist between those with intention to get vaccinated and those actually vaccinated, indicating a potential to increase vaccination coverage rate in the future. Our study shows that stable vaccination coverage rates were observed from 2002 to 2006 in Great Britain. The coverage had increased in Wales and in Scotland. The coverage among the elderly above 65 years was the highest in Europe. Although Great Britain complies with national and international goals of vaccination coverage rates effort is needed to ensure high vaccination coverage rates at the same level in the future.     

Trends of influenza infection in Egypt during two consecutive seasons

Background  Influenza is a zoonotic disease caused by a variety of the RNA flu virus. Influenza is a winter illness in temperate climates. Influenza seasons differ each year in length and severity. The viruses are grouped into three types, A, B and C. The emergence of new influenza A viruses could lead to pandemics. Aim  Study the effect of some sociodemographic risk factors on the development of influenza infection among Egyptians in two consecutive seasons, 2004–2005 and 2005–2006. Subjects and methods  This cross-sectional study of influenza seasons 2005 and 2006 was carried out on influenza-like illness (ILI) patients in clinics in urban and rural areas in Qualiubia governorate. The study included 468 subjects; nasal and throat swabs were collected from these patients in the two seasons for a total of 50 weeks. Some sociodemographic parameters were studied. Immuonfluorescence antibody (IFA) test was performed for fresh samples. Isolation was done in embryonated eggs. Hemagglutination and hemagglutination inhibition tests were done to determine and identify virus isolates. The isolates were sent to the World Health Organization Collaborating Centre (WHOCC, London) for confirmation, making more studies and sharing in annual vaccine production. Results  In season 2005, 42.4% of ILI subjects were positive for influenza (88 were type A and 1 was type B). The incidence of influenza infection among children younger than 10 years was 83.1%. Nearly three quarters (74.2%) of recorded cases came from low socio-economic level groups. In the 2006 season, 50% (131 subjects) of the total ILI subjects were positive for influenza [127 patients were type A (22 of them were subtyped as H1N1) and 4 were type B]. The incidence of influenza infection among children younger than 10 years was 88.5%. Nearly two thirds (65.6%) of recorded cases belong to low socio-economic level groups. Conclusion  Type A was more prevalent than type B, and the activity peak of influenza was in December, especially week 49.     

Influenza vaccination coverage against seasonal and pandemic influenza and their determinants in France: a cross-sectional survey

Background  

Following the emergence of the influenza A(H1N1)2009 virus, the French ministry of health decided to offer free vaccination against pandemic influenza to the entire French population. Groups of people were defined and prioritised for vaccination.     

Measuring maternal Tdap and influenza vaccination rates: Comparison of two population-based methods

Pregnant women are routinely recommended to receive Tdap and influenza vaccines to prevent disease and complications among mothers and newborns. Monitoring population trends in maternal vaccination is important in order to evaluate the implementation of these recommendations and to identify pockets of need. We present two methods for measuring maternal vaccination among a state population and discuss the strengths and drawbacks of each method. First, we matched maternal information from records of Wisconsin births during 2013–2015 with maternal vaccination records in the Wisconsin Immunization Registry. Second, we used an all-payer health insurance claims database to identify Wisconsin women with deliveries during 2013–2015 and vaccinations received during pregnancy. Both methods produced similar trends and indicated a substantial increase in the percentage of women receiving Tdap during pregnancy, and lower vaccination rates among women who were Medicaid-insured. When available and timely, both methods are useful for monitoring maternal vaccination.     

Influenza vaccination coverage rates in the UK: a comparison of two monitoring methods during the 2002-2003 and 2003-2004 seasons

OBJECTIVES: To assess the feasibility of measuring influenza vaccination coverage during 2002-2003 and 2003-2004 seasons using a telephone survey; to compare these findings with routine vaccine uptake monitoring based on data provided by general practitioners. STUDY DESIGN: Telephone-based survey. METHODS: We interviewed a random sample of non-institutionalized individuals representative of the population aged 16 years and over. Four target groups were determined for analysis: (1) people aged 65 years and over; (2) healthcare workers; (3) people under 65 years with chronic illnesses, which placed them at risk for influenza; and (4) a group composed of all three previous groups combined. RESULTS: The overall sample consisted of 4054 people (about 2000 per season). Population influenza vaccine coverage in the UK increased from 22.3% in 2002-2003 to 24.2% in 2003-2004. Vaccine uptake was strongly age dependent, even in people aged 65 years and over (the ages at which all people are routinely targeted). In both seasons, the estimates of vaccine uptake in people aged 65 years and over were remarkably consistent with those obtained through routine monitoring. Vaccine uptake in healthcare workers was markedly suboptimal. CONCLUSIONS: In the UK, a telephone-based system of monitoring influenza vaccine uptake seems robust enough to generate data that are comparable with routine vaccine monitoring undertaken using data provided by general practitioners. Although such a system cannot easily contribute towards monitoring of vaccination at local and regional levels, it offers a validated method of estimating vaccine uptake that is independent of healthcare workers' time. This may be especially important for a pandemic vaccination programme, especially in countries in which healthcare resources are scarce, or where the configuration of healthcare services is less conducive to internal monitoring than is the case in the UK.     

Factors influencing on influenza vaccination and its trends of coverage in patients with diabetes in Korea: A population-based cross-sectional study

BackgroundInfluenza infection is a contagious disease and annual influenza vaccination is recommended to the patients with chronic diseases. Although diabetes is an indication for influenza vaccination, the global rate of influenza vaccination is insufficient. Therefore, our study aimed to elucidate influenza vaccination statuses among patients with diabetes and the related factors in Korea.MethodsA total of 32,268 subjects (4,540 with and 27,728 without diabetes) from the Korea National Health and Nutrition Examination Survey III–VI (2005–2015) were included. Socioeconomic factors and health-related factors were analyses for the relation of influenza vaccination by Student's t-test, the chi-squared test and a multivariate logistic regression analysis.ResultsThe influenza vaccination coverage rates were 50.0% in the diabetes mellitus (DM) group and 38.2% in the non-DM group. The trends in influenza vaccination rates during KNHANES III–VI were not significant in each group (P trend = 0.24 in the DM group, 0.30 in the non-DM group). Socioeconomic (older age, female sex, higher family income, and medical aid insurance) and health-related factors (lack of risky alcohol consumption, obesity, and recent health check-ups) were associated with influenza vaccination among patients with DM.ConclusionsThe rate of influenza vaccination among patients with diabetes is insufficient in Korea. More efforts are needed to increase the influenza vaccination rates among vulnerable at-risk populations.     

Influenza vaccination coverage of population and the factors influencing influenza vaccination in mainland China: A meta-analysis

IntroductionThe best way to prevent influenza is receiving vaccination. However, the influenza vaccination coverage in mainland China was low. A meta-analysis was conducted to estimate the vaccination rates of the population and the factors influencing influenza vaccination in mainland China.MethodsA systematic study was conducted on March 18, 2018, using Chinese language databases including China National Knowledge Infrastructure, Chinese Science and Technology Periodical Database, WanFang Database, and English language databases including PubMed, Web of Science, and Cochrane Library. Based on the inclusion and exclusion criteria, the pooled coverage rate and estimated odds ratios (OR) of influencing factors were obtained using data abstraction. Subgroup analysis and meta-regression analysis were also employed to explore the heterogeneity.ResultsThe pooled vaccination coverage rate in 126 included articles was 23.2% (95% confidence interval (CI): 22.8%, 23.7%), and the pooled vaccination rate among the general population was 9.4% (95% CI: 8.0%, 10.9%). The influenza vaccination rate fluctuated from 2005 to 2017. Vaccination rates in 2009–2010 were much higher than other years, pandemic influenza vaccination rate was 37.3% (95% CI: 28.4%, 46.1%) and seasonal influenza vaccination rate was 29.8% (95% CI: 24.6%, 34.9%). In the analysis of influencing factors, those recommended by healthcare workers was the most reported reasons for influenza vaccination with an OR = 5.2 (95% CI: 2.9, 9.4), and following as received influenza vaccination previously, perceived safety of vaccination, perceived effectiveness of vaccination, perceived severity of the disease. Meta-regression analysis indicate that the heterogeneity maybe significantly consistent with the sample size, study population, study region, and vaccination policy.ConclusionCompared with other countries (the United States), vaccination rates were lower in mainland China. There were a few factors influencing the rate, which included vaccination policy, vaccination history and knowledge and attitudes toward influenza and vaccination.     

Influenza vaccination coverage and reasons to refrain among high-risk persons in four European countries

This paper examines influenza vaccine coverage using a population base of an average of 2300 persons in each of four European countries (Germany, Spain, Poland and Sweden). The reasons for non-vaccination of those in the high-risk groups were explored by questionnaire. The vaccine coverage rate (VCR) for elderly ranged from 18% in Poland to 67% in Spain. The VCR for high-risk population under 65 was 10% in Poland, 13% in Sweden, 27% in Germany and 30% in Spain. The most important reasons mentioned for not being vaccinated were: perceived sufficient resistance to flu (33-42%) in all countries; financial barriers in Poland (25%), and not to qualify for the vaccination (30%) and forgetfulness (20%) in Germany. Receiving a personal invitation for the vaccination, results in higher coverage rates in all four countries. We think that future interventions could be directed towards: an information campaign with special attention to the high-risk groups due to disease; promotion of personal invitations; and, for Poland, solving financial barriers to vaccination.     

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

AimsTo examine influenza vaccination coverage among risk groups (RG) and health care workers (HCW), and study social and demographic patterns of vaccination coverage over time.MethodsVaccination coverage was estimated by self-report in a nationally representative telephone survey among 14 919 individuals aged 18–79 years over seven influenza seasons from 2014/15 to 2020/21. We explored whether belonging to an influenza RG (being >=65 years of age and/or having >=1 medical risk factor), being a HCW or educational attainment was associated with vaccination status using logistic regression.ResultsVaccination coverage increased from 27 % to 66 % among individuals 65–79 years, from 13 % to 33 % among individuals 18–64 years with >=1 risk factor, and from 9 % to 51 % among HCWs during the study period. Being older, having a risk factor or being a HCW were significantly associated with higher coverage in all multivariable logistic regression analyses. Higher education was also consistently associated with higher coverage, but the difference did not reach significance in all influenza seasons. Educational attainment was not significantly associated with coverage while coverage was at its lowest (2014/15–2017/18), but as coverage increased, so did the differences. Individuals with intermediate or lower education were less likely to report vaccination than those with higher education in season 2018/19, OR = 0.61 (95 % CI 0.46–0.80) and OR = 0.58 (95 % CI 0.41–0.83), respectively, and in season 2019/20, OR = 0.69 (95 % CI 0.55–0.88) and OR = 0.71 (95 % CI 0.53–0.95), respectively. When the vaccine was funded in the COVID-19 pandemic winter of 2020/21, educational differences diminished again and were no longer significant.ConclusionsWe observed widening educational differences in influenza vaccination coverage as coverage increased from 2014/15 to 2019/20. When influenza vaccination was funded in 2020/21, differences in coverage by educational attainment diminished. These findings indicate that economic barriers influence influenza vaccination decisions among risk groups in Norway.     

Antibody response to influenza immunization in two consecutive epidemic seasons in patients with renal diseases

The aim of this study was to assess antihemagglutinin and antineuraminidase antibody kinetics in 26 patients with renal diseases vaccinated against influenza in two consecutive epidemic seasons. Antibody responses were measured before immunization and 1, 3 and 6 months after immunization. Antihemagglutinin (HI) antibodies were determined by the hemagglutinin inhibition test and antineuraminidase (NI) antibody levels by the neuraminidase inhibition test. After vaccination HI and NI antibody titers significantly increased when compared with the pre-vaccination levels. Three months after vaccination the protection rates ranged from 50 to 61.5% in the 1995/96 season and 100% for all antigens in the 1996/97 season. Response rates ranged from 50 to 57.7% and 93.8 to 100% respectively. Significantly higher humoral response was recorded in the 1996/97 season than in the 1995/96 season. No serious adverse reactions were observed in the vaccinated patients and no symptoms of influenza or influenza-like infection were noted. In spite of some doubts about the safety and efficacy of influenza vaccination in patients from high-risk groups, the results of this study showed that many of them are able to produce HI antibodies in titers which are sufficient to protect against the influenza infection.     

Assessment of vaccination coverage, vaccination scar rates, and smallpox scarring in five areas of West Africa

In 1966, nineteen countries of West and Central Africa began a regional smallpox eradication and measles control programme in cooperation with the World Health Organization. This paper summarizes sample survey data collected to assess the results of the programme in Northern Nigeria (Sokoto and Katsina Provinces), Western Nigeria, Niger, Dahomey, and Togo. These data indicate that the programme, which used mass vaccination campaigns based on a collecting-point strategy, was generally successful in reaching a high proportion of the population. Analysis of vaccination coverage and vaccination scar rates by age underlined the importance to the programme of newborn children who accumulate rapidly following the mass campaign. Of all persons without vaccination scars at the time of the surveys, 34.4% were under 5 years of age; in the absence of a maintenance programme, this figure would rise to 40% after 1 year.     

Influenza vaccination coverage among children with asthma--United States, 2004-05 influenza season

In 2005, approximately 8.9% (6.5 million) of U.S. children aged <18 years were reported to have current asthma. Children with asthma are at high risk for complications from influenza, and influenza vaccination has been determined to safely and effectively reduce rates of influenza in these children. Since its establishment in 1964, the Advisory Committee on Immunization Practices (ACIP) has recommended that all children with asthma aged > or =6 months receive vaccination with inactivated influenza vaccine during each influenza season; however, national influenza vaccination coverage rates specifically for children with asthma have not been determined. Previous studies have assessed influenza vaccination rates in children with asthma at the local level using health maintenance organization and clinician group-practice information, with estimates ranging from 10% to 43% for various influenza seasons. Another study used Behavioral Risk Factor Surveillance System (BRFSS) data to estimate influenza vaccination coverage in children aged 2-17 years with one or more conditions putting them at high risk for complications from influenza (including asthma, although asthma was not assessed separately); in that study, the national rate was estimated at 34.8% for the 2004-05 influenza season (based on a sample size of 685, which included all states and the District of Columbia [DC]). To estimate national influenza vaccination coverage rates among children aged 2-17 years with current asthma, CDC analyzed data from the 2005 National Health Interview Survey (NHIS). This report describes the results of that analysis and provides the first national estimates of influenza vaccination coverage among children with asthma. The findings indicated that although children with current asthma were more likely to receive influenza vaccination than children without current asthma, the vaccination coverage rate among children with asthma was low, at 29.0% (95% confidence interval [CI] = 24.5-33.9). These findings underscore the need to increase influenza vaccination coverage in children with asthma aged 2-17 years by identifying and overcoming barriers to vaccination.     

Monitoring pandemic influenza A(H1N1) vaccination coverage in Germany 2009/10 - results from thirteen consecutive cross-sectional surveys

To monitor pandemic influenza A(H1N1) vaccine uptake during the vaccination campaign in Germany 2009/10, thirteen consecutive cross-sectional telephone-surveys were performed between November 2009 and April 2010. In total 13,010 household-interviews were conducted. Vaccination coverage in persons >14 years of age remained low, both in the general population (8.1%; 95%CI: 7.4-8.8) and in specific target groups such as healthcare workers and individuals with underlying chronic diseases (12.8%; 95%CI: 11.4-14.4). Previous vaccination against seasonal influenza was a main factor independently associated with pandemic influenza vaccination (Odds ratio = 8.8; 95%CI: 7.2-10.8). The campaign failed to reach people at risk who were not used to receive their annual seasonal influenza shot.     

Influenza vaccination coverage among persons with asthma--United States, 2005-06 influenza season

During 2006, approximately 6.8 million (9.3%) U.S. children and 16.1 million (7.3%) U.S. adults were reported to have asthma. Since 1964, the Advisory Committee on Immunization Practices (ACIP) has recommended influenza vaccination of all persons with asthma because of the higher risk for medical complications from influenza for those persons. Influenza vaccination coverage of persons with asthma varies by age group and remains below Healthy People 2010 targets of 60% coverage of persons aged 18--64 years with high-risk conditions (14-29 c) and 90% of all persons aged > or =65 years (14-29 a). Influenza vaccination rates of children and older adults with asthma have not been well studied. Using 2006 National Health Interview Survey (NHIS) data, this report provides the first examination of influenza vaccination rates and related factors across a national sample of persons with asthma aged > or =2 years. The results indicated that 36.2% received influenza vaccination during the 2005--06 influenza season. Vaccination rates remained below target levels among all subgroups examined, including those reporting the greatest number of health-care visits in the past 12 months. The results of this study indicate that influenza vaccination coverage of all persons with asthma can be improved by increasing access to health care and using opportunities for vaccination during health-care visits.     

Influenza vaccination in paediatric nurses: cross-sectional study of coverage, refusal, and factors in acceptance

BACKGROUND: Influenza vaccination among health-care workers is poor, and the effectiveness of hospital vaccination programs remains unclear. Little is known about the effectiveness of intensive evidence-based vaccination programs in nursing staff. We determined whether the recommended vaccination rate could be achieved among paediatric nurses during an intensive promotional program for influenza vaccination. We also sought to identify the reasons for which nurses refuse the influenza vaccine and predictors of future vaccination intent. METHODS: We offered influenza vaccination to nursing staff during an influenza season through a multi-component program that included intensive promotional activities. We analysed vaccination data to determine uptake rates. In a cross-sectional survey, self-administered questionnaires were distributed to all nurses with patient contact during that season. The questionnaire evaluated their vaccine use, site of work, absenteeism and physician visits due to respiratory illness, vaccination intent for the subsequent influenza season, and other items. We surveyed vaccinated nurses regarding their program experiences and the frequency and severity of adverse reactions. Unvaccinated nurses were asked their reasons for refusing vaccination. Multiple logistic-regression analysis was conducted to identify variables that predicted the likelihood of future vaccine acceptance. RESULTS: More than 75% (895/1,182) of applicable nurses were vaccinated in the program. The questionnaire response rate was nearly 48% (585/1,230). Vaccination in the program during the current season (odds ratio [OR] 101.99, 95% confidence interval [CI] 52.54-197.98), program convenience (OR 199.19, 95% CI 98.01-404.11), and a physician visit for respiratory illness (OR 2.44, 95% CI 1.29-4.61) were found to be independent predictors of intent to receive the vaccine the following season. A lack of perceived personal need was the most common reason for vaccine refusal, given in 30% (77/258) of unvaccinated respondents. CONCLUSIONS: Adequate coverage of nurses is achievable during an intensive voluntary immunisation program against influenza, using best-known practices. Perceived lack of personal benefit is a major deterrent, while program convenience and previous vaccination strongly predict future vaccine acceptance. Our findings support interventions that improve the convenience of hospital immunisation programs for influenza, particularly those that are aimed at nurses and that promote vaccine efficacy and benefits.     

Rapid assessment of influenza vaccination coverage among HMO members--northern California influenza seasons, 2001-02 through 2004-05

The Vaccine Safety Datalink (VSD) is a collaborative project involving CDC and eight health maintenance organizations (HMOs) in the United States. Computerized data on vaccination, medical outcomes, and patient demographics are collected and linked under a standard protocol at multiple HMOs. Beginning with the 2003-04 influenza season, the VSD team and one of the HMOs, Kaiser Permanente Northern California (KPNC), established an automated system for rapid detection of potentially adverse events after vaccinations among its members. During the 2004-05 influenza season, in response to the influenza vaccine shortfall and resulting prioritization of vaccine distribution, this rapid analysis system also was used to assess influenza vaccination coverage weekly among KPNC members. The results indicated that KPNC followed Advisory Committee on Immunization Practices (ACIP) prioritization guidelines by targeting influenza vaccination to children aged 6-23 months and adults aged >/=65 years. For the 2005-06 influenza season, the rapid analysis system should be expanded to include data from additional HMOs and more detailed information on vaccinees (e.g., high risk for influenza complications) to better characterize influenza vaccination coverage during the 2005-06 influenza season on a weekly basis.