Developing mRNA vaccines in low- and middle-income countries is important for global pandemic preparedness. This study compared the safety and immune response of “Comvigen,” a bivalent COVID-19 vaccine, with the standard vaccine “Comirnaty.” In this phase II randomised trial in Thailand, 450 participants who had received at least two prior COVID-19 vaccine doses (with the last mRNA dose more than three months before enrolment) were assigned to receive either Comvigen or Comirnaty. Researchers measured neutralizing antibodies against the original virus and Omicron (BA.4/BA.5) at day 29 and monitored side effects for six months. The results showed that Comvigen induced an immune response that was not inferior to Comirnaty for both variants. Although local and systemic reactions were slightly more frequent with Comvigen, most were mild to moderate and resolved on their own, with no difference in fever rates. These findings support the development of mRNA vaccines to improve access and strengthen preparedness for future pandemics.

Read more: https://pmc.ncbi.nlm.nih.gov/articles/PMC12849096/

First Author: Watsamon Jantarabenjakul

Co-author: Arunee Thitithanyanont

Corresponding Author: Kiat Ruxrungtham