INTRODUCTION
Vaccinating school-age children with a third dose (booster) of a COVID-19 vaccine is an urgent public health need as this population remains vulnerable to COVID-19 and may transmit SARS-CoV-2, particularly of highly transmissible variants. In a phase 2/3 study conducted before the Omicron wave, a BNT162b2 vaccine two-dose primary series given 21 days apart was immunogenic and 91% effective against COVID-19 in 5- to 11-year olds [