Evaluation of Safety, Tolerability, Reactogenicity, Immunogenicity of Baiya SARS-CoV-2 Vax 2 as a Booster for COVID-19

This is a Phase 2, randomised, and double-blinded study. The participants will be randomised to receive either the investigational product or the placebo at a ratio of 2:1. 0.5 mL of the assigned vaccine will be administered as an IM injection. Each participant will be followed up for 6 months after vaccination. The primary objective aims to assess the safety, tolerability, and reactogenicity of Baiya SARS-CoV-2 Vax 2 vaccine in adults (18-64 years old) as a booster vaccination following vaccination with the alternate and widely used COVID-19 vaccines. The secondary objective aims to evaluate safety, tolerability, reactogenicity, and immunogenicity up to 28 days after the booster vaccination. An interim analysis of all safety and available immunogenicity data up to Visit 6 (Day 29 ±3) will be conducted for the DSMB review.