ABSTRACT
Purpose. In 2024, COVID-19 vaccination became mandatory in Brazil for children aged 6 months to 4 years. In Brazil, the product available for this purpose is the Pfizer BNT162b2 Messenger RNA COVID-19 Vaccine, whose potential risks related to long-term human genomic changes are still uncertain compared to immunizations based on other platforms. Methods. the epidemiology of Severe Acute Respiratory Syndrome was evaluated in Brazil, in the years 2022 and 2023, in children aged 6 months to 4 years, based on available public data. Results. The number needed to treat (NNT) with BNT162b2 to prevent one death from COVID-19 in this age group can range from 208,856 to 548,246. The number needed to harm (NNH) to cause a vaccine-associated death can range from 42,373 to 909,090. Conclusions. The results of this study indicate a borderline short-term risk/benefit ratio of BNT162b2 vaccine for the Brazilian population aged 6 months to 4 years. Given that there is no clear benefit from its mandatory use in this age group and the uncertainty regarding potential risks to human health in the long term due to possible retroposition (reverse transcription) with incorporation into the genome of parts of the genetic sequence introduced into humans as RNA exogenous by BNT162b, it is recommended that its use should not be mandatory and that vaccines based on other platforms should remain available, ensuring the right to informed choice by the health system users.