Heterologous ChAdOx1-S/BNT162b2 Vaccination
Résumé
Dear Editor,
A recent report questioned whether one vaccine was better than another and how to evaluate this difference, but only homologous vaccination schedules were considered. Concern about the safety of the ChAdOx1-S vaccine have prompted some European countries to recommend using a heterologous booster, as proposed for mRNA vaccines for people under 55 years old . Immunogenicity and reactogenicity of a BNT162b2 booster in ChAdOx1-S-primed subjects was assessed in a multicenter, open-label, randomised, controled phase 2 trial, but included no homologous vaccination comparator. Few studies have compared the immune responses to homologous and heterologous vaccination
schedules in humans.