A Seamless Phase II/III, Observer-blind, to Evaluate Immunogenicity and Safety of Chikungunya Virus Vaccine in Healthy Subjects 12-65Years of Age. (CHIKV/II-III)

The current study is designed to evaluate the safety, immunogenicity, and lot-to-lot consistency of the BBV87 40 μg vaccine in healthy subjects.This Phase III study is a randomized, observer blind, placebo-controlled, multi-centre, lot-to-lot consistency study with a two-dose schedule. Approximately, 1000 healthy subjects 12 to 65 years of age will be randomized irrespective of CHIKV serological status at Visit 1. Nine hundred subjects will be randomized equally among three lots of BBV87 40 μg. (Lot A, Lot B,and Lot C) while 100 subjects will be administered a placebo. Thus, approximately 1000 subjects will be randomized in allocation ratio 3:3:3:1 (BBV87 40 μg. Lot A: BBV87 40 μg. Lot B: BBV87 40 μg. Lot C: Placebo). Subjects will receive 40 μg dose strength of BBV87, based on the dose approved by the DSMB and CDSCO in the Phase II study. After Day 56, the DSMB will review the safety data during the study to safeguard the interests of trial subjects and assess the vaccine's safety.