Immunological and Hepatic Responses to ChAdOx1-S/nCoV-19 Vaccination in Brazilian Academic Volunteers

COVID-19 is caused by the SARS-CoV-2 coronavirus. Vaccine development was essential for reducing hospitalizations and mortality during the pandemic. In Brazil, the ChAdOx1-S/nCoV-19 (AstraZeneca) vaccine was widely administered during the initial phase of the national immunization campaign. Despite a well-established safety profile, continuous surveillance of adverse events remains important. Mild adverse reactions occurred more frequently after the first dose and were generally self-limiting. The vaccine induced a strong IgG antibody response, demonstrating robust immunogenicity while producing minimal changes in liver function parameters. These findings support the favorable safety, tolerability, and immunogenic profile of the ChAdOx1-S/nCoV-19 vaccine in this population.