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Publications (13)22.3 Total impact

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    ABSTRACT: Objectives: Target groups for seasonal influenza vaccination are nationally defined based on several factors. However, few studies have explored the policy-making processes at the country-level. We investigated key differences in the policy-making process for the development of vaccination recommendations between France (FR) and The Netherlands (NL). This paper presents preliminary results on the evidence used in the decision-making process and focuses on the interactions between the experts and stakeholders. Methods: A documentary analysis identified the stakeholders of this process as governmental authorities, research institutions, associations, and manufacturers. This qualitative study included at least one expert from each stakeholder group. Thirty-three semi-structured interviews were performed in 2013 (16 FR, 17 NL). We used NVivo10® to perform a thematic content analysis on the data. Results: National Immunization Technical Advisory Groups (NITAGs) were the key stakeholders in the development of recommendations. There was no systematic standard evaluation of evidence during the decision-making process in both countries. Likewise, voting was not systematic, although it did occur more often in FR. A declaration of interests was obligatory in both countries. Experts with no conflicts of interest were rare because many depend on private funding for their research on influenza vaccination. Conclusions: The transparency of the NITAGs' procedures for the development of recommendations should be improved. We believe improvements might be achieved by the systematic standard evaluation of evidence, consistent voting, clear declarations of interest, and increased public funding for vaccination research.
    No preview · Article · Jan 2016 · Health Policy
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    ABSTRACT: Influenza B represents a high proportion of influenza cases in some seasons (even over 50%). The Influenza B study in General Practice (IBGP) is a multicenter study providing information about the clinical, demographic and socio-economic characteristics of patients affected by lab-confirmed influenza A or B. Influenza B patients and age-matched influenza A patients were recruited within the sentinel surveillance networks of France and Turkey in 2010–11 and 2011–12 seasons. Data were collected for each patient at the swab test day, after 9±2 days and, if not recovered, after 28±5 days. It was related to patient's characteristics, symptoms at presentation, vaccination status, prescriptions of antibiotics and antivirals, duration of illness, follow-up consultations in general practice or emergency room. We performed descriptive analyses and developed a multiple regression model to investigate the effect of patients and disease characteristics on the duration of illness. Overall, 774 influenza cases were included in the study: 419 influenza B cases (209 in France and 210 in Turkey) and 355 influenza A cases (205 in France and 150 in Turkey). There were no differences between influenza A and B patients in terms of clinical presentation and number of consultations with a practitioner; however, the use of antivirals was higher among influenza B patients in both countries. The average (median) reported duration of illness in the age groups 0–14 years, 15–64 years and 65+ years was 7.4 (6), 8.7 (8) and 10.5 (9) days in France, and 6.3 (6), 8.2 (7) and 9.2 (6) days in Turkey; it increased with age but did not differ by virus type; increased duration of illness was associated with antibiotics prescription. In conclusion, our findings show that influenza B infection appears not to be milder disease than influenza A infection.
    Full-text · Article · Oct 2015 · PLoS ONE
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    ABSTRACT: Studies that aimed at comparing the clinical presentation of influenza patients across virus types and subtypes/lineages found divergent results, but this was never investigated using data collected over several years in a countrywide, primary care practitioners-based influenza surveillance system. The IBVD (Influenza B in Vircases Database) study collected information on signs and symptoms at disease onset from laboratory-confirmed influenza patients of any age who consulted a sentinel practitioner in France. We compared the clinical presentation of influenza patients across age groups (0-4, 5-14, 15-64 and 65+ years), virus types (A, B) and subtypes/lineages (A(H3N2), pandemic A(H1N1), B Victoria, B Yamagata). Overall, 14,423 influenza cases (23.9% of which were influenza B) were included between 2003-2004 and 2012-2013. Influenza A and B accounted for over 50% of total influenza cases during eight and two seasons, respectively. There were minor differences in the distribution of signs and symptoms across influenza virus types and subtypes/lineages. Compared to patients aged 0-4 years, those aged 5-14 years were more likely to have been infected with type B viruses (OR 2.15, 95% CI 1.87-2.47) while those aged 15-64 years were less likely (OR 0.83, 95% CI 0.73-0.96). Males and influenza patients diagnosed during the epidemic period were less likely to be infected with type B viruses. Despite differences in age distribution, the clinical illness produced by the different influenza virus types and subtypes is indistinguishable among patients that consult a general practitioner for acute respiratory infections.
    Full-text · Article · Sep 2015 · PLoS ONE
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    ABSTRACT: Describing the circulation of influenza viruses and the characteristics of seasonal epidemics remains an essential tool to optimize the strategies of influenza prevention and control. Special attention has been recently paid to influenza B in the context of the availability of a quadrivalent vaccine, containing two influenza B strains. We used data from a practitioners-based influenza surveillance network to describe the circulation of influenza viruses in France from 2003-2004 to 2012-2013. Nasopharyngeal swabs taken from acute respiratory infection (ARI) patients between October and April were tested for influenza. We reported the number of influenza cases by virus type (A, B), subtype (A(H1), A(H3)) and B lineage (Yamagata, Victoria) in each season and determined the frequency of influenza B vaccine mismatch. We estimated weekly incidence of influenza by extrapolating reported influenza cases to the French population. We compared the temporal characteristics of the epidemics caused by influenza A(H1), A(H3) and B. Overall, 49,919 ARI patients were tested, of which 16,287 (32.6 %) were positive for influenza. Type B virus caused 23.7 % of all influenza cases. Virus subtypes A(H1) and A(H3) caused 51.6 % and 48.4 % of influenza A cases, respectively. Viruses of the B-Yamagata and B-Victoria lineage caused 62.8 % and 37.2 % of influenza B cases, respectively. There was an influenza B vaccine mismatch in three of the five seasons where influenza B caused 10 % or more of all influenza cases. Influenza A(H3) had the highest average value of estimated weekly incidence during the study period. Influenza B peaked an average 3.8 weeks later than influenza A when both virus types were circulating. No differences in the duration of influenza A and B epidemics were observed. Influenza A(H3) was the most prevalent influenza type during the study period. Influenza B caused around one fourth of all influenza cases and tended to circulate later than influenza A. The frequency of influenza B vaccine mismatches was substantial. Timely data on the circulation of influenza viruses collected within influenza surveillance systems are essential to optimize influenza prevention and control strategies.
    Full-text · Article · Aug 2015 · BMC Infectious Diseases
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    ABSTRACT: To conduct a literature review of influenza vaccination policy, describing roles and interactions between stakeholders and the factors influencing policy-making. Major databases were searched using keywords related to influenza vaccination, decision-making and healthpolicy. Titles and abstracts were screened according to defined criteria using independent reviewers. Selected articles were analysed and compared against a checklist. 342 papers were identified, but only 111 included. A wide range of countries was represented in articles published in 1994-2012. We identified numerous stakeholders at the national and international level and found a variety of interactions between them. Using these data, we suggest a scheme for the most important stakeholders and their interactions. Determinants of policy-making were mainly related to the vaccine/disease, political-economic context, and stakeholders communication. The most relevant evidence was clinical/epidemiological studies. After the 2009 pandemic: the importance of mathematical modelling and ethical issues was greater; and the need for better communication between stakeholders was emphasised. The relevance of evidence and factors influencing policy-making varied between countries, according to complex interactions between the stakeholders involved at different levels of decision-making process. These interactions remain unclear, especially at national level, where the most important influenza policy decisions are made. To better define and understand the exact interactions and use of evidence, we recommend undertaking future qualitative studies at national level using small number of countries. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
    No preview · Article · Apr 2015 · Health Policy
  • Jean Marie Cohen · Maria-Laura Silva · Saverio Caini

    No preview · Article · Jan 2015
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    ABSTRACT: In France, 2-15% of the population is affected annually by influenza, which causes significant socioeconomic disruption. Nevertheless, despite its importance for policy makers, few published studies have evaluated the impact of influenza B. Therefore, we assessed the costs associated with influenza B during 2010-2011 in France. Cases of lab-confirmed influenza B were analyzed as part of the Influenza B in General Practice Study. Cost calculations were based on micro-costing methods according to the French Health Insurance (FHI) perspective (in Euros, 2011). Costs were compared between age groups using the Kruskal-Wallis test, and when significant, by multiple comparisons based on rank. Moreover, uncertainties were assessed using one-way sensitivity and probabilistic analyses. Overall economic burden was estimated by multiplying cost per patient, flu attack rate, and the French population. A total of 201 patients were included in the study. We found that the mean cost associated with Influenza B was 72[euro sign] (SD: 205) per patient: 70[euro sign] (SD: 262) for younger children, 50[euro sign] (SD: 195) for older children, 126[euro sign] (SD: 180) for adults, and 42[euro sign] (SD: 18) for elderly. Thus, we observed significantly different costs between the distinct age groups (p<0.0001). Finally, the economic burden of influenza B for the FHI was estimated to be 145 million Euros (95% CI: 88-201). Our findings highlight the important impact of influenza B and encourage further investigation on policy regarding vaccination strategies in France.
    Full-text · Article · Jan 2014 · BMC Public Health

  • No preview · Article · Jan 2012
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    ABSTRACT: In the third season of I-MOVE (Influenza Monitoring Vaccine Effectiveness in Europe), we undertook a multicentre case-control study based on sentinel practitioner surveillance networks in eight European Union (EU) member states to estimate 2010/11 influenza vaccine effectiveness (VE) against medically-attended influenza-like illness (ILI) laboratory-confirmed as influenza. Using systematic sampling, practitioners swabbed ILI/ARI patients within seven days of symptom onset. We compared influenza-positive to influenza laboratory-negative patients among those meeting the EU ILI case definition. A valid vaccination corresponded to > 14 days between receiving a dose of vaccine and symptom onset. We used multiple imputation with chained equations to estimate missing values. Using logistic regression with study as fixed effect we calculated influenza VE adjusting for potential confounders. We estimated influenza VE overall, by influenza type, age group and among the target group for vaccination. We included 2019 cases and 2391 controls in the analysis. Adjusted VE was 52% (95% CI 30-67) overall (N = 4410), 55% (95% CI 29-72) against A(H1N1) and 50% (95% CI 14-71) against influenza B. Adjusted VE against all influenza subtypes was 66% (95% CI 15-86), 41% (95% CI -3-66) and 60% (95% CI 17-81) among those aged 0-14, 15-59 and ≥60 respectively. Among target groups for vaccination (N = 1004), VE was 56% (95% CI 34-71) overall, 59% (95% CI 32-75) against A(H1N1) and 63% (95% CI 31-81) against influenza B. Results suggest moderate protection from 2010-11 trivalent influenza vaccines against medically-attended ILI laboratory-confirmed as influenza across Europe. Adjusted and stratified influenza VE estimates are possible with the large sample size of this multi-centre case-control. I-MOVE shows how a network can provide precise summary VE measures across Europe.
    Full-text · Article · Nov 2011 · PLoS ONE
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    ABSTRACT: In this study, we assess how effective pandemic and trivalent 2009-2010 seasonal vaccines were in preventing influenza-like illness (ILI) during the 2009 A(H1N1) pandemic in France. We also compare vaccine effectiveness against ILI versus laboratory-confirmed pandemic A(H1N1) influenza, and assess the possible bias caused by using non-specific endpoints and observational data. We estimated vaccine effectiveness by using the following formula: VE  =  (PPV-PCV)/(PPV(1-PCV)) × 100%, where PPV is the proportion vaccinated in the population and PCV the proportion of vaccinated influenza cases. People were considered vaccinated three weeks after receiving a dose of vaccine. ILI and pandemic A(H1N1) laboratory-confirmed cases were obtained from two surveillance networks of general practitioners. During the epidemic, 99.7% of influenza isolates were pandemic A(H1N1). Pandemic and seasonal vaccine uptakes in the population were obtained from the National Health Insurance database and by telephonic surveys, respectively. Effectiveness estimates were adjusted by age and week. The presence of residual biases was explored by calculating vaccine effectiveness after the influenza period. The effectiveness of pandemic vaccines in preventing ILI was 52% (95% confidence interval: 30-69) during the pandemic and 33% (4-55) after. It was 86% (56-98) against confirmed influenza. The effectiveness of seasonal vaccines against ILI was 61% (56-66) during the pandemic and 19% (-10-41) after. It was 60% (41-74) against confirmed influenza. The effectiveness of pandemic vaccines in preventing confirmed pandemic A(H1N1) influenza on the field was high, consistently with published findings. It was significantly lower against ILI. This is unsurprising since not all ILI cases are caused by influenza. Trivalent 2009-2010 seasonal vaccines had a statistically significant effectiveness in preventing ILI and confirmed pandemic influenza, but were not better in preventing confirmed pandemic influenza than in preventing ILI. This lack of difference might be indicative of selection bias.
    Full-text · Article · May 2011 · PLoS ONE
  • Martine Valette · Anne Mosnier · Jean Marie Cohen · Bruno Lina
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    ABSTRACT: In France, the surveillance of influenza epidemics is carried out through a community-based surveillance network combining clinical and virological data. This surveillance is implemented in the Rhône-Alpes region, including the large ski resorts. In these resorts, numerous tourists are coming from France as well as from other European countries throughout the entire ski season. A specific network has been implemented in the ski resorts of the Alps (GROG-SKI) to analyse the circulation of influenza in these villages. Since winter 2001–2002, 11 GPs in seven resorts have been collecting virological specimens from patients presenting with acute respiratory infections, including both natives and visitors. During the last winter period, we compared the circulation of influenza in the GROG-SKI network with the circulation of influenza in the Rhône-Alpes region, with the exclusion of the departments of the Alps (Savoie and Haute-Savoie). Overall, from the 15th of December until the 15th of April, 105 samples were collected in the GROG-SKI network, compared with 495 in the other departments of the Rhône-Alpes region; influenza being detected in 34 (32.4%) and 187 (37.8%) specimens, respectively (p=0.2). The peaks were observed at the same period, in mid-February, with the same shift from Influenza B to Influenza A viruses by the end of March. Within the Rhône-Alpes region, the influenza epidemic was observed at the same period of time in the ski resorts and in the remaining part of the region during winter 2002–2003; both surveillance yielding identical epidemic curves. This result suggests that the tourists coming to the ski resorts are exposed to the risk of developing influenza according to the epidemic status of the region, and that they have a minor impact on the epidemiology of influenza viruses in the ski resorts.
    No preview · Article · Jun 2004 · International Congress Series
  • Jean Marie Cohen · Anne Mosnier · Isidore Grog

    No preview · Article · Mar 2003 · Medecine sciences: M/S
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