Abstract
BACKGROUND: Mongolia has a high prevalence of liver disease from chronic viral hepatitis infections, which can compromise the immune response. It is unclear whether people with chronic liver disease produce a robust antibody response to the COVID-19 vaccines. We investigated whether the antibody response to the COVID-19 booster vaccination differed between those with and without chronic viral hepatitis from multiple viral types. METHODS: Participants from Mongolia were recruited to the International Study on COVID-19 Vaccine to Assess Immunogenicity, Reactogenicity and Efficacy (InVITE). Demographic information was recorded and participants’ SARS-CoV2 anti-Spike antibody levels were measured at visit 1 (prior to administration of booster vaccine at baseline) and visit 2 (approximately 2 +/-1 months after booster vaccination). We used linear regression to determine if the anti-Spike antibody responses differed between participants with and without different types of chronic viral hepatitis infections. RESULTS: Overall, there was no significant difference in the anti-Spike antibody response between participants with and without chronic viral hepatitis, a result suggesting that COVID-19 vaccine booster immunogenicity is not affected by chronic hepatitis. Participants with chronic HCV infection produced a robust antibody response, but based on our linear regression analysis, this response seemed to wane faster than in participants without chronic viral hepatitis. CONCLUSIONS: Our finding that there was no significant difference in the anti-Spike antibody response between participants with and without chronic viral hepatitis adds to the evidence that the COVID-19 vaccines are immunogenic in people with chronic viral hepatitis, including in those with HBV/HDV coinfection. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12879-026-13095-y.