Participants in stable health will be randomly assigned into one of four groups based on their age to receive either 6 µg of BBV152 or placebo in a 1:1 ratio. Each participant will receive 2 doses of the study vaccine by 0.5 mL intramuscular injection, the first on Day 0 and the second on Day 28. Data will be collected in an observer-blind manner.~Safety will be monitored by the Data and Safety Monitoring Board. The Data and Safety Monitoring Board will convene to perform safety reviews at 2 and 6 months and for immediate concerns regarding safety observations as needed.~Safety assessment will include monitoring solicited, unsolicited, serious, medically attended adverse events and potentially immune medicated medical conditions.~Since this is a bridging study, the maximum sample size of the data from the previous study will be 31 samples from the <65 years population and 358 with samples from the 18 to <65 years population.
A randomized, observer-blind, placebo-controlled immuno-bridging, and broadening study to demonstrate the equivalence of the immune response between participants enrolled in Phase 3 efficacy trial in India and demographically diverse healthy adult participants in the US which matched in age and vaccine formulation setting to whom those efficacy results are extrapolated; and to assess the broadening of the BBV152 in participants who previously received two shots of messenger ribonucleic acid (mRNA) COVID-19 vaccine at least 6 months earlier or one-shots of viral vector J&J/Janssen COVID-19 vaccine at least 2 months earlier. Safety and tolerability evaluation is a secondary endpoint.