Pfizer vaccine is moderately effective at preventing COVID-19 in 5-11 year olds
30 Jun 2022
A large observational study to evaluate how well the Pfizer vaccine protects children aged 5-11 shows moderate protection from two doses. These results were published yesterday in the New England Journal of Medicine.
This is one of the first large cohort studies to evaluate the effectiveness of the Pfizer BNT162b2 pediatric Covid-19 vaccine in children as the Omicron variant became dominant. The study compared rates of Covid-19 in 94,728 vaccinated children, 5 to 11 years of age, with 94,728 rigorously matched unvaccinated controls.
The estimated short-term vaccine effectiveness was moderate: 51% against documented SARS-CoV-2 infection and 48% against symptomatic Covid-19 illness, during days 7-21 following the second dose. The younger children seemed to receive greater protection than the older children in this study.
The study was conducted at Israel's largest healthcare organization, Clalit Health Services, in collaboration with researchers from Harvard University, the University of Padua and the MRC CTU at UCL.
Israel was one of the first countries to launch a campaign to vaccinate children 5-11 years of age in November 2021. This nationwide study provides early evidence on the effectiveness of the pediatric Covid-19 vaccine. This is the first peer-reviewed cohort study to control for differences between the two study groups across many characteristics, including demographic factors, number of chronic medical conditions and health seeking behaviour.
This study represents an international collaboration of researchers from Israel, the United States and Europe, as part of the Ivan and Francesca Berkowitz Family Living Laboratory Collaboration between the Clalit Research Institute and Harvard University in the United States, and as part of the VERDI Project funded by the European Union Horizon Program. Professor Ali Judd, based at the MRC CTU at UCL and one of the co-authors of this paper, is the VERDI Scientific Coordinator
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