Effectiveness of influenza vaccination of schoolchildren in the city of São Paulo, Brazil, 2009

Abstract

BackgroundChildren 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.MethodsThis 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.ResultsA 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).ConclusionVaccination of schoolchildren significantly protected them and their household contacts against seasonal influenza.

Reduction in self-reported influenza-like-illness in school children and household members following influenza vaccine administration – a cohort study, Israel, 2016–7

“…The results found in this study are compatible with the upper range of vaccine effectiveness (VE) of 42–65.0%, which was demonstrated in Hong Kong and Sao Paulo, respectively [ 10 , 11 ]. In the CDC report for seasonal influenza vaccine effectiveness in 2016–2017, adjusted vaccine effectiveness for all ages was 40%, and for age group 9–17 years vaccine effectiveness was 36% [ 12 ].…”

Acceptance and feasibility of school-based seasonal influenza vaccination in Singapore: A qualitative study

“…While the existing evidence demonstrates that the introduction of seasonal SIVPs can have substantial health [4][5][6][7][8][9][10][26][27][28] and economic [29,30] benefits for the wider community, this and of 27 previous studies [15,[31][32][33][34][35][36][37] suggest that the successful implementation of such programmes may depend on more qualitative, context-specific aspects. A review of SIVPs in high-income countries identified considerable administrative and logistical challenges to the successful delivery of vaccines in schools, including the choice of organisational and funding models, the logistics of vaccine supply and distribution, issues around staff capacity and workload, and communication with parents and students [35].…”

“…There is substantial evidence of indirect protective benefits to unvaccinated groups from vaccinating school-aged children [4][5][6][7][8][9][10][26][27][28][43][44][45][46][47][48][49][50]. However, the majority of evidence on the impact and cost-effectiveness of seasonal SIVPs comes from studies in North America and Europe, which have different vaccine financing mechanisms and influenza epidemiology compared to Singapore.…”

“…The World Health Organization currently recommends annual vaccination of children aged 6-59 months [3]. Data from high and middle-income countries show that seasonal influenza vaccination of preschool-and school-aged children can effectively reduce the incidence of influenza among vaccines [4][5][6][7][8][9][10], and confer indirect protection to unvaccinated individuals in the community [11,12].…”

Sepsis, parenteral vaccination and skin disinfection

“…The prevalence of cellulitis in the 6 randomized, controlled trials collated 45-50 in this review ranged from 1/143 to 1/22,070 injections with the mean being 1/5290 injections. If the 2 extreme outliers are excluded then mean prevalence of cellulitis is 1/2383 injections.…”