Open AccessEffectiveness of influenza vaccination of schoolchildren in the city of S ão P aulo, B razil, 2009
Author(s) -
Gattás Vera L.,
Cardoso Maria Regina A.,
Mondini Gabriela,
Machado Clarisse M.,
Luna Expedito J. A.
Publication year - 2015
Publication title -
influenza and other respiratory viruses
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.743
H-Index - 57
eISSN - 1750-2659
pISSN - 1750-2640
DOI - 10.1111/irv.12328
Subject(s) - vaccination , medicine , transmission (telecommunications) , live attenuated influenza vaccine , virus , seasonal influenza , virology , influenza vaccine , influenza a virus , immunology , covid-19 , disease , infectious disease (medical specialty) , electrical engineering , engineering
Background Children play an important role in maintaining the transmission of influenza. Evidence suggests that vaccination of school‐age children can reduce transmission to unvaccinated household contacts. We evaluated the direct and indirect effectiveness of the 2009 inactivated seasonal influenza vaccine in vaccinated schoolchildren and their unvaccinated household contacts. Methods This was a double‐blind cluster randomized trial involving 10 schools and 1742 schoolchildren as well as 5406 household contacts. The schools were randomly assigned to receive the influenza vaccine or the control vaccine. After vaccination, the schoolchildren and household contacts were followed for 6 months to identify cases of acute respiratory infection ( ARI ). Reverse‐transcriptase polymerase chain reaction was performed for the diagnosis of influenza. Results A total of 632 ARI cases were detected. Of those, 103 tested positive for influenza virus (influenza virus A[H1N1]pdm09 virus in 55 and seasonal influenza viruses in 48). The effectiveness of the vaccine in protecting against seasonal influenza virus infection was 65·0% for the household contacts (95% CI , 19·6–84·3) and 65·0% for the schoolchildren (95% CI , 20·9–84·5). Conclusion Vaccination of schoolchildren significantly protected them and their household contacts against seasonal influenza.