68 research outputs found

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

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    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. METHODS: We took a random sample of the population of mainland France and conducted a retrospective cross-sectional telephone survey to estimate vaccination coverage against seasonal and pandemic influenza and to identify determinants of these vaccinations. RESULTS: 10,091 people were included in the survey. Overall seasonal influenza vaccination coverage (IVC) remained stable in the population from the 2008-2009 season to the 2009-2010 season reaching 20.6% and 20.8% respectively. Overall pandemic IVC in the French population is estimated to be 11.1% (CI95%: 9.8 - 12.4). The highest pandemic IVC was observed in the 0-4 years age group. For individuals with health conditions associated with higher risk of influenza, pandemic IVC was estimated to be 12.2% (CI95%: 9.8 - 15.1). The main determinants associated with pandemic influenza vaccine uptake were: living in a household with a child < 5 years OR(adj): 2.0 (CI95%: 1.3 - 3.1) or with two children < 5 years or more, OR(adj): 2.7 (CI95%: 1.4 - 5.1), living in a household where the head of the family is university graduate (>2 years), OR(adj): 2.5 (CI95%: 1.5 - 4.1), or has a higher professional and managerial occupation, OR(adj): 3.0 (CI95%: 1.5 - 5.5) and being vaccinated against seasonal influenza, OR(adj): 7.1 (CI95%: 5.1 - 10.0). Being an individual with higher risk for influenza was not a determinant for pandemic influenza vaccine uptake. These determinants are not the same as those for seasonal influenza vaccination. CONCLUSIONS: Overall A(H1N1)2009 influenza vaccine uptake remained low, particularly among individuals with higher risk for influenza and was lower than that observed for seasonal influenza. The reasons behind people's reluctance to be vaccinated need to be investigated further

    Monitoring the proportion of the population infected by SARS-CoV-2 using age-stratified hospitalisation and serological data: a modelling study.

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    BACKGROUND: Regional monitoring of the proportion of the population who have been infected by SARS-CoV-2 is important to guide local management of the epidemic, but is difficult in the absence of regular nationwide serosurveys. We aimed to estimate in near real time the proportion of adults who have been infected by SARS-CoV-2. METHODS: In this modelling study, we developed a method to reconstruct the proportion of adults who have been infected by SARS-CoV-2 and the proportion of infections being detected, using the joint analysis of age-stratified seroprevalence, hospitalisation, and case data, with deconvolution methods. We developed our method on a dataset consisting of seroprevalence estimates from 9782 participants (aged ≄20 years) in the two worst affected regions of France in May, 2020, and applied our approach to the 13 French metropolitan regions over the period March, 2020, to January, 2021. We validated our method externally using data from a national seroprevalence study done between May and June, 2020. FINDINGS: We estimate that 5·7% (95% CI 5·1-6·4) of adults in metropolitan France had been infected with SARS-CoV-2 by May 11, 2020. This proportion remained stable until August, 2020, and increased to 14·9% (13·2-16·9) by Jan 15, 2021. With 26·5% (23·4-29·8) of adult residents having been infected in Île-de-France (Paris region) compared with 5·1% (4·5-5·8) in Brittany by January, 2021, regional variations remained large (coefficient of variation [CV] 0·50) although less so than in May, 2020 (CV 0·74). The proportion infected was twice as high (20·4%, 15·6-26·3) in 20-49-year-olds than in individuals aged 50 years or older (9·7%, 6·9-14·1). 40·2% (34·3-46·3) of infections in adults were detected in June to August, 2020, compared with 49·3% (42·9-55·9) in November, 2020, to January, 2021. Our regional estimates of seroprevalence were strongly correlated with the external validation dataset (coefficient of correlation 0·89). INTERPRETATION: Our simple approach to estimate the proportion of adults that have been infected with SARS-CoV-2 can help to characterise the burden of SARS-CoV-2 infection, epidemic dynamics, and the performance of surveillance in different regions. FUNDING: EU RECOVER, Agence Nationale de la Recherche, Fondation pour la Recherche MĂ©dicale, Institut National de la SantĂ© et de la Recherche MĂ©dicale (Inserm)

    Estimated number of deaths directly averted in people 60 years and older as a result of COVID-19 vaccination in the WHO European Region, December 2020 to November 2021

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    Since December 2019, over 1.5 million SARS-CoV-2-related fatalities have been recorded in the World Health Organization European Region - 90.2% in people ≄ 60 years. We calculated lives saved in this age group by COVID-19 vaccination in 33 countries from December 2020 to November 2021, using weekly reported deaths and vaccination coverage. We estimated that vaccination averted 469,186 deaths (51% of 911,302 expected deaths; sensitivity range: 129,851-733,744; 23-62%). Impact by country ranged 6-93%, largest when implementation was early.S

    Demographic and Clinical Factors Associated with Response to Smallpox Vaccine in Preimmunized Volunteers

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    CONTEXT: In March 2003, the French Ministry of Health implemented a program on preparedness and response to a biological attack using smallpox as weapon. This program included the establishment of a preoutbreak national team that could be revaccinated against smallpox. OBJECTIVE: To identify demographic and clinical factors associated with vaccination success defined as the presence of a pustule at the inoculation site at day 8 (days 7-9), with an undiluted vaccinia virus derived from a Lister strain among preimmunized volunteers. VOLUNTEERS AND METHODS: From March 2003 to November 2006, we have studied prospectively 226 eligible volunteers. Demographic data were recorded for each volunteer (age, sex, number of previously smallpox vaccinations and date of the last vaccination). Smallpox vaccine adverse reactions were diagnosed on the basis of clinical examination performed at days 0, 7, 14, 21 and 28 after revaccination. RESULTS: A total of 226 volunteers (sex ratio H/F = 2.7) were revaccinated. Median age was 45 years (range: 27-63 yrs). All volunteers completed follow-up. Median number of vaccinations before revaccination was 2 (range: 1-8). The median delay between time of the study and the last vaccination was 29 years (range; 18-60 yrs). Sixty-one volunteers (27%) experienced one (n = 40) or more (n = 21) minor side effects during the 2-14 days after revaccination. Successful vaccination was noted in 216/226 volunteers (95.6%) at day 8 and the median of the pustule diameter was 5 mm (range: 1-20 mm). Size of the pustule at day 8 was correlated with age (p = 0.03) and with the presence of axillary adenopathy after revaccination (p = 0.007). Sex, number of prior vaccinations, delay between the last vaccination and revaccination, and local or systemic side effects with the exception of axillary adenopathy, were not correlated with the size of the pustule at day 8. CONCLUSIONS: Previously vaccinated volunteers can be successfully revaccinated with the Lister strain

    Immunisation of migrants in EU/EEA countries: Policies and practices

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    In recent years various EU/EEA countries have experienced an influx of migrants from low and middle-income countries. In 2018, the “Vaccine European New Integrated Collaboration Effort (VENICE)” survey group conducted a survey among 30 EU/EEA countries to investigate immunisation policies and practices targeting irregular migrants, refugees and asylum seekers (later called “migrants” in this report). Twenty-nine countries participated in the survey. Twenty-eight countries reported having national policies targeting children/adolescent and adult migrants, however vaccinations offered to adult migrants are limited to specific conditions in seven countries. All the vaccinations included in the National Immunisation Programme (NIP) are offered to children/adolescents in 27/28 countries and to adults in 13/28 countries. In the 15 countries offering only certain vaccinations to adults, priority is given to diphtheria-tetanus, measles-mumps-rubella and polio vaccinations. Information about the vaccines given to child/adolescent migrants is recorded in 22 countries and to adult migrants in 19 countries with a large variation in recording methods found across countries. Individual and aggregated data are reportedly not shared with other centres/institutions in 13 and 15 countries, respectively. Twenty countries reported not collecting data on vaccination uptake among migrants; only three countries have these data at the national level. Procedures to guarantee migrants’ access to vaccinations at the community level are available in 13 countries. In conclusion, although diversified, strategies for migrant vaccination are in place in all countries except for one, and the strategies are generally in line with international recommendations. Efforts are needed to strengthen partnerships and implement initiatives across countries of origin, transit and destination to develop and better share documentation in order to guarantee a completion of vaccination series and to avoid unnecessary re-vaccination. Development of migrant-friendly strategies to facilitate migrants' access to vaccination and collection of vaccination uptake data among migrants is needed to meet existing gaps

    Bases des Recommandations vaccinales

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    Le processus d’élaboration des recommandations vaccinales, fondĂ© sur l’établissement de la balance entre les bĂ©nĂ©fices et les risques, est un processus complexe et continu. Il fait appel Ă  une expertise largement multidisciplinaire, prenant en compte des facteurs Ă©pidĂ©miologiques, immunologiques, mais aussi sociaux, Ă©conomiques et politiques. Il repose essentiellement sur des donnĂ©es Ă©pidĂ©miologiques mais fait de maniĂšre croissante appel Ă  des outils sophistiquĂ©s de modĂšlisation mathĂ©matique et d’évaluation mĂ©dico-Ă©conomique. Les dĂ©cisions doivent intĂ©grer des concepts mal dĂ©finis tels que le prix accordĂ© par notre sociĂ©tĂ© Ă  la prĂ©vention d’un dĂ©cĂšs d’enfant ou plus largement Ă  une annĂ©e de vie sauvĂ©e, les niveaux de risque d’effets secondaires et de maladies acceptables ou l’aspect collectif de la stratĂ©gie vaccinale interfĂ©rant avec la libertĂ© de choix individuelle

    Monitoring the reproductive number of COVID-19 in France: Comparative estimates from three datasets

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    International audienceBackground: The effective reproduction number (R t ) quantifies the average number of secondary cases caused by one person with an infectious disease. Near-real-time monitoring of R t during an outbreak is a major indicator used to monitor changes in disease transmission and assess the effectiveness of interventions. The estimation of R t usually requires the identification of infected cases in the population, which can prove challenging with the available data, especially when asymptomatic people or with mild symptoms are not usually screened. The purpose of this study was to perform sensitivity analysis of R t estimates for COVID-19 surveillance in France based on three data sources with different sensitivities and specificities for identifying infected cases. Methods: We applied a statistical method developed by Cori et al. to estimate R t using (1) confirmed cases identified from positive virological tests in the population, (2) suspected cases recorded by a national network of emergency departments, and (3) COVID-19 hospital admissions recorded by a national administrative system to manage hospital organization. Results: R t estimates in France from May 27, 2020, to August 12, 2022, showed similar temporal trends regardless of the dataset. Estimates based on the daily number of confirmed cases provided an earlier signal than the two other sources, with an average lag of 3 and 6 days for estimates based on emergency department visits and hospital admissions, respectively. Conclusion: The COVID-19 experience confirmed that monitoring temporal changes in R t was a key indicator to help the public health authorities control the outbreak in real time. However, gaining access to data on all infected people in the population in order to estimate R t is not straightforward in practice. As this analysis has shown, the opportunity to use more readily available data to estimate R t trends, provided that it is highly correlated with the spread of infection, provides a practical solution for monitoring the COVID-19 pandemic and indeed any other epidemic
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