Safety and immunogenicity of SARS-CoV-2 protein subunit recombinant vaccine (Indovac®) in healthy populations aged 18 years and above in Indonesia: A phase I, observer-blind, randomized, controlled study

Indonesian vaccine producer (PT BIOFARMA), conducted a study to assess the safety and immunogenicity of a new COVID-19 vaccine candidate. This vaccine is based on a recombinant subunit protein platform, with the SARS-CoV-2 receptor-binding domain (RBD) as its target antigen. The study compared the candidate's safety and immunogenicity to the control group vaccine, the Sinovac vaccine, 28 days after administration. This was an observer-blinded and randomized Phase 1 trial which recruited 175 subjects. The subject received 0.5 ml of vaccine in two doses. The subjects were split into five treatment groups, consisting of different combinations of doses between RBD and CpG. The safety of this vaccine was evaluated within 7 days after the first dose and for 6 months after the second dose, while the immunogenicity was evaluated on days 14 and 28 after the second dose. The overall incidence of AEs was 54.86% from the beginning of the vaccination to 28 days after each injection. Most AEs were local pain and had no serious AEs. The study revealed a significant rise in the Geometric Mean Titer (GMT) of IgG antibodies in every group, indicating a strong immune response. The phase I data demonstrated that the new vaccine candidate showed promising results in safety and immunogenicity.