Vaccination coverage rates in eleven European countries during two consecutive influenza seasons
Introduction
Influenza is caused by a contagious respiratory virus that appears annually in the autumn through early spring, causing substantial morbidity and mortality.1 The World Health Organisation (WHO) estimates three to five million cases annually, resulting in a mortality rate of 250,000–500,000 in the industrialized world.1 In Europe, the rate of excess deaths due to influenza is estimated at 40,000–220,000 cases per season.2
The clinical and economic burden of the influenza epidemics is often undervalued. Incapacitating symptoms lead an increased demand in all health care systems, long-term illness and disability as well as mortality. Some individuals are more susceptible to develop severe disease due to an infection.3, 4 Influenza-related complications occur more often and more severely in groups at higher risk of pneumonia or respiratory disease, cardiovascular diseases and metabolic disorders.5, 6, 7, 8 These complications are responsible for a 50–100-times higher death rate among people with underlying illnesses.9 A further group exposed to higher risk of fatal complications are the elderly. The declining functioning of the immune system with age and the increasing presence of chronic medical conditions lead to increased susceptibility and mortality.10 The fact that the elderly are at higher risk for influenza is reported by the WHO and also by the literature.11 Children pose a further target group where the existence of chronic underlying medical condition amplifies the risk of complications.12 In the US, the yearly influenza cases among children are estimated at 10–40% resulting in hospitalisation in about one percent.12, 13
The cornerstone of influenza prevention is vaccination.1, 14 Influenza vaccination has been demonstrated to be highly cost-efficient or cost saving.15, 16 Vaccination leads to lower incidence of influenza-related respiratory diseases and sever complications, to lower health care costs for influenza treatment, prevention and hospitalisation as well as to reduced death cases especially among the elderly population. Employees who acquire influenza lose on average two days at their working place.17 However, lost (absenteeism) or condensed (presenteeism) productivity at the working place or at home can be reduced by the help of vaccinating the population.18, 19, 20
In May 2003, the World Health Assembly (WHA) released recommendations for the usage of influenza vaccines. These recommendations are targeted at all people at risk, meaning the elderly population and individuals with underlying diseases.21 The Member states of the European Union are engaged to attain the goal of 75% vaccination coverage by 2010 in the elderly population.22 All European countries have official policies in regard to influenza vaccination. The actual national regulations in all countries recommend the vaccine to the elderly population (≥65 years in Czech Republic, Finland, France, Ireland, Italy, Portugal, Spain, UK; ≥60 years in Germany; ≥50 years in Poland; Austria recommends the vaccine to all age groups) and to patients with impairing medical conditions like chronic pulmonary diseases (including asthma), cardiovascular diseases (except hypertension), renal or hepatic diseases (except Czech Republic, Italy, France), haematological or metabolic disorders (including diabetes mellitus) and immunologic disorders including HIV/AIDS (except Czech Republic). The vaccination of pregnant women is recommended in Austria, Italy, Portugal and Spain. Furthermore, vaccinating of health care professionals is also recommended.23 The paediatric conventions recommend influenza vaccine to children older than six months with cardiac or renal diseases, diabetes, compromised immune system, HIV-positive status (with the exception of Austria, Czech Republic, Finland, Italy, Portugal) or under long-term aspirin usage (except Austria, Czech Republic, Germany, Poland, UK).24, 25 Austria and Finland (since 2007/08) are the only European countries with a recommendation for healthy children aged 6–23 month of age.26, 27
Even though the vaccination coverage rates particularly among at-risk groups are increasing, the usage of influenza vaccines is still suboptimal. While some countries are on a good way to reach the targets of the WHO by 2010, others will not be able to follow.
The aim of this cross-sectional survey was to identify the disparities of influenza coverage rates in eleven European countries during two consecutive influenza seasons. Besides focusing the vaccine uptake among at-risk groups and children, the project also aimed at investigating the driving factors and barriers towards vaccination.
Section snippets
Study design
A population-based cross-sectional survey was carried out in the UK, Germany, Italy, France, Spain, Austria, Czech Republic, Finland, Ireland, Poland and Portugal. During the two consecutive influenza seasons 2006/07 and 2007/08, representative household surveys were conducted using telephone surveys, mailed questionnaires or face-to-face interviews. The method of the fieldwork was described earlier.28 In brief, telephone interviews were conducted by TNS health care, using a computer-assisted
Vaccination and intention rates in the general population
Table 1 presents characteristics of the survey population of the season 2007/08. There were no unexpected data points.
Vaccination coverage rates for influenza seasons 2006/07 and 2007/08 are indicated in Fig. 1. During season 2007/08, the highest overall coverage was found in the UK (28.7%, 95% CI 26.7–30.7%), the lowest in Poland (9.5%, 95% CI 8.5–11.5%). Compared to the year before, statistically significant changes were found in UK (p = 0.008), Finland (p = 0.003) and Poland (p ≤ 0.001). The
Discussion and conclusion
Our survey showed that vaccination coverage rates in the general population of eleven European countries ranged from 9.5% to 28.7% during season 2007/08. Compared to the year before, there were hardly any increases, except in the UK and Finland. The discrepancy between intended and real vaccination rates was considerable in all countries. In season 2007/08, belonging to one of the defined target groups for vaccination was a predictor for getting vaccinated. Individuals older than 65 years of
Funding source
This study was made possible by an unrestricted, educational grant from the European Vaccine Manufacturers Group of the European Federation of Pharmaceutical Industries and Associations (EFPIA), Brussels, Belgium.
Acknowledgment
We thank the GEIG (Groupe d'Etude et d'Information pour la Grippe) for making the data of France available for this analysis. Authors' contribution: PB performed the data analysis, contributed to the data interpretation and wrote the manuscript. MS contributed to data analysis, data interpretation and the final version of the manuscript. TS designed the project, contributed to the data acquisition and the analysis and supervised its development. All authors have read and approved the final
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All authors have made substantial contributions to all of the following: (1) the conception and design of the study, or acquisition of data, or analysis and interpretation of data, (2) drafting the article or revising it critically for important intellectual content, (3) final approval of the version to be submitted.