Enrollment for BNT164a1 and BNT164b1 will be conducted independently, and in parallel. The trial will enroll participants divided into six cohorts by dose level (3 doses levels per vaccine, i.e., BNT164a1 and BNT164b1) who will be randomized 7:1 to BNT164 (BNT164a1 or BNT164b1):placebo. The trial will use a staggered dose escalation schema with sentinel participants for Dose 1 in all cohorts.
This randomized, placebo-controlled, double-blind, safety and dose-finding Phase Ia trial will evaluate three dose levels of the BNT164 investigational vaccines (BNT164a1 and BNT164b1) to select a safe and tolerable dose in a three-dose schedule.