PLoS Medicine: Estimates of Pandemic Influenza Vaccine Effectiveness in Europe, 2009–2010: Results of Influenza Monitoring Vaccine Effectiveness in Europe (I-MOVE) Multicentre Case-Control Study

Estimates of Pandemic Influenza Vaccine Effectiveness in Europe, 2009–2010: Results of Influenza Monitoring Vaccine Effectiveness in Europe (I-MOVE) Multicentre Case-Control Study

Results from a European multicentre case-control study reported by Marta Valenciano and colleagues suggest good protection by the pandemic monovalent H1N1 vaccine against pH1N1 and no effect of the 2009–2010 seasonal influenza vaccine on H1N1.

Marta Valenciano1*, Esther Kissling1, Jean-Marie Cohen2, Beatrix Oroszi3, Anne-Sophie Barret4,5, Caterina Rizzo6, Baltazar Nunes7, Daniela Pitigoi8,9, Amparro Larrauri Cámara10, Anne Mosnier2, Judith K. Horvath3, Joan O'Donnell4, Antonio Bella6, Raquel Guiomar7, Emilia Lupulescu8, Camelia Savulescu1,10, Bruno C. Ciancio11, Piotr Kramarz11, Alain Moren1

1 EpiConcept, Paris, France, 2 Réseau des GROG/Open Rome, Paris, France, 3 National Center for Epidemiology, Budapest, Hungary, 4 Health Protection Surveillance Centre, Dublin, Ireland, 5 European Programme for Intervention Epidemiology Training (EPIET), European Centre for Disease Prevention and Control, Stockholm, Sweden, 6 National Centre for Epidemiology, Surveillance and Health Promotion, Istituto Superiore di Sanità, Roma, Italy, 7 Instituto Nacional de Saúde Dr Ricardo Jorge, Lisbon, Portugal, 8 Cantacuzino Institute, National Institute of Research – Development for Microbiology and Immunology, Bucharest, Romania, 9 Universitatea de Medicina si Farmacie Carol Davila, Bucharest, Romania, 10 National Centre for Epidemiology, Instituto de Salud Carlos III, Madrid, Spain, 11 European Centre for Disease Prevention and Control (ECDC), Stockholm, Sweden

Abstract
Background
A multicentre case-control study based on sentinel practitioner surveillance networks from seven European countries was undertaken to estimate the effectiveness of 2009–2010 pandemic and seasonal influenza vaccines against medically attended influenza-like illness (ILI) laboratory-confirmed as pandemic influenza A (H1N1) (pH1N1).

Methods and Findings
Sentinel practitioners swabbed ILI patients using systematic sampling. We included in the study patients meeting the European ILI case definition with onset of symptoms >14 days after the start of national pandemic vaccination campaigns. We compared pH1N1 cases to influenza laboratory-negative controls. A valid vaccination corresponded to >14 days between receiving a dose of vaccine and symptom onset. We estimated pooled vaccine effectiveness (VE) as 1 minus the odds ratio with the study site as a fixed effect. Using logistic regression, we adjusted VE for potential confounding factors (age group, sex, month of onset, chronic diseases and related hospitalizations, smoking history, seasonal influenza vaccinations, practitioner visits in previous year). We conducted a complete case analysis excluding individuals with missing values and a multiple multivariate imputation to estimate missing values. The multivariate imputation (n = 2902) adjusted pandemic VE (PIVE) estimates were 71.9% (95% confidence interval [CI] 45.6–85.5) overall; 78.4% (95% CI 54.4–89.8) in patients <65 years; and 72.9% (95% CI 39.8–87.8) in individuals without chronic disease. The complete case (n = 1,502) adjusted PIVE were 66.0% (95% CI 23.9–84.8), 71.3% (95% CI 29.1–88.4), and 70.2% (95% CI 19.4–89.0), respectively. The adjusted PIVE was 66.0% (95% CI −69.9 to 93.2) if vaccinated 8–14 days before ILI onset. The adjusted 2009–2010 seasonal influenza VE was 9.9% (95% CI −65.2 to 50.9).

Conclusions
Our results suggest good protection of the pandemic monovalent vaccine against medically attended pH1N1 and no effect of the 2009–2010 seasonal influenza vaccine. However, the late availability of the pandemic vaccine and subsequent limited coverage with this vaccine hampered our ability to study vaccine benefits during the outbreak period. Future studies should include estimation of the effectiveness of the new trivalent vaccine in the upcoming 2010–2011 season, when vaccination will occur before the influenza season starts.

Please see later in the article for the Editors' Summary

Citation: Valenciano M, Kissling E, Cohen J-M, Oroszi B, Barret A-S, et al. (2011) Estimates of Pandemic Influenza Vaccine Effectiveness in Europe, 2009–2010: Results of Influenza Monitoring Vaccine Effectiveness in Europe (I-MOVE) Multicentre Case-Control Study. PLoS Med 8(1): e1000388. doi:10.1371/journal.pmed.1000388

Academic Editor: Lone Simonsen, George Washington University, United States of America


Received: May 25, 2010; Accepted: November 22, 2010; Published: January 11, 2011

Copyright: © 2011 Valenciano et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Funding: This project received funding from the European Centre for Disease Prevention and Control (ECDC, http://www.ecdc.europa.eu) through the call for tender FWC ECDC/07/015. ECDC uses only public money and P. Kramarz and B. C. Cianco (coauthors of the article and working for ECDC) have no conflicts of interest to declare. P. Kramarz and B. C. Ciancio collaborated with EpiConcept in setting up the system, deciding on study design, and writing the article.

Competing interests: J-M Cohen is a direct advisor for the French Minister of Health (MOH). His salary as Head of réseau des GROG is financed by the French MOH (76%) and Institut Pasteur (24%). The Institut Pasteur contribution is funded by a pool of five pharmaceutical firms (Roche, Glaxo SmithKline [GSK], Sanofi Pasteur, Solvay, Argène). As Head of Open Rome, he is involved in several epidemiological studies that are partially or fully funded by pharmaceutical companies (Sanofi-Pasteur, GSK, Roche), nonprofit organizations (Mutuelles, Résaeu DES France) or public institutions (ECDC, CU Strasbourg). He is a member of Association Mieux Prescrire and the advisory boards of Novartis, Roche, and Wyeth (free participation, no compensation). During the past five years, he has received travel grants from Sanofi-Pasteur and Roche. A. Mosnier is a member of the French MOH advisory board on influenza, and adviser for influenza to the French Health Insurance organization. As coordinator of the Réseau des GROG (French Influenza Sentinel network), her salary is funded by MOH (76%) and Institut Pasteur (24%). Institut Pasteur contribution is funded by a pool of five pharmaceutical firms (GSK, Roche, Sanofi-Pasteur, Solvay, Argène). She is involved, through the other institution with which she is affiliated and salaried (Open Rome research department), in the coordination or analysis of epidemiological studies partially or fully funded by Roche and GSK. She is member of the Groupe d'Expertise et d'Information sur la Grippe (GEIG) Scientific Board. During the last five years, she has received travel grants from Roche for speaking, or participation, at scientific meetings. All other authors have declared that no competing interests exist.

Abbreviations: ARI, acute respiratory infection; CI, confidence interval; EU, European Union; GP, general practitioner; ILI, influenza-like illness; PIVE, pandemic influenza vaccine effectiveness; SIVE, seasonal influenza vaccine effectiveness; VE, vaccine effectiveness

* E-mail: m.valenciano@epiconcept.fr

full-text:
PLoS Medicine: Estimates of Pandemic Influenza Vaccine Effectiveness in Europe, 2009–2010: Results of Influenza Monitoring Vaccine Effectiveness in Europe (I-MOVE) Multicentre Case-Control Study




GRIPE H1N1
Actualidad Ultimas noticias - JANOes y agencias -
La vacuna de la gripe A/H1N1 resultó eficaz hasta en un 100%
JANO.es y agencias · 12 Enero 2011 09:24

Un estudio francés muestra que las vacunas de la gripe pandémica utilizadas en siete países, entre ellos España, proporcionaron una buena protección frente al virus la temporada pasada.




La vacuna de la gripe A resultó eficaz, según un estudio internacional coordinado desde el EpiConcept en París, Francia, y que se publica en la revista PLoS Medicine. Los resultados del trabajo muestran que una dosis de las vacunas de la gripe pandémica utilizadas en siete países europeos proporcionó una buena protección frente a la gripe H1N1 en la estación de 2009-2010, en especial en personas menores de 65 años y en aquellos sin enfermedades crónicas.

Los autores realizaron un estudio multicéntrico basado en redes de vigilancia médica en siete países: Francia, Hungría, Irlanda, Italia, Rumanía, Portugal y España. Los pacientes con síntomas similares a los de la gripe proporcionaron muestras nasales o de garganta en los ocho días siguientes al inicio de los síntomas. Se consideraba que una persona había sido vacunada si había recibido una dosis de la vacuna más de 14 días antes de la fecha de inicio de los síntomas gripales y no vacunada si no habían recibido la dosis o si ésta se había proporcionado en un plazo menor a los 15 días previos al comienzo de los síntomas.

Los autores analizaron la eficacia de la vacunación en los vacunados en un plazo menor a los 8 días, los vacunados entre los 8 y los 14 días y aquellos vacunados más de 14 días antes del inicio de los síntomas, en comparación con quienes no fueron vacunados.

Los resultados obtenidos durante la fase avanzada de la pandemia sugieren una buena protección con la vacuna para el H1N1 pandémico, de hecho, la eficacia se estima entre el 65% y el 100%. Los descubrimientos también sugieren que la vacuna de la gripe estacional de 2009-2010, a diferencia de la vacuna para el H1N1, no protegieron frente a la gripe pandémica H1N1.

Según los autores, la disponibilidad tardía de la vacuna pandémica y la posterior limitación en la cobertura obstaculizaron la capacidad de estudio de los beneficios de la vacuna durante el período pandémico. Además, los investigadores señalan que futuros estudios deberían incluir una estimación de la eficacia de la nueva vacuna trivalente en la estación 2010-2011, cuando se produzca la vacunación antes de que comience la estación de gripe.


PLoS Med 8(1): e1000388. doi:10.1371/journal.pmed.1000388
PLoS Medicine: Estimates of Pandemic Influenza Vaccine Effectiveness in Europe, 2009–2010: Results of Influenza Monitoring Vaccine Effectiveness in Europe (I-MOVE) Multicentre Case-Control Study

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Actualidad Ultimas noticias - JANOes y agencias - La vacuna de la gripe A/H1N1 resulto eficaz hasta en un 100 - JANO.es - ELSEVIER