Effectiveness of BNT162B2 and CoronaVac vaccines in reducing COVID-19 severity among children aged 3-4 years in Brazil.
INTRODUCTION National population-based databases from large countries can provide real-world estimates of COVID-19 vaccine effectiveness. This analysis examined the effectiveness of BNT162b2 and CoronaVac against severe COVID-19-related outcomes in children aged 3 to 4 years during the Omicron phase of the pandemic in...