The persistent circulation of SARS-CoV-2 represents an ongoing global threat due to the emergence of new viral variants that can sometimes evade the immune system of previously exposed or vaccinated individuals. We conducted a follow-up study of adult individuals that had received an inactivated SARS-CoV-2 vaccine, evaluating antibody production and neutralizing activity over a period of 6 months. In addition, we performed mice immunization with inactivated SARS-CoV-2, and evaluated the immune response and pathological outcomes against Gamma and Zeta variant infection. Vaccinated individuals produced high levels of antibodies with robust neutralizing activity, which was significantly reduced against Gamma and Zeta variants. Production of IgG anti-S antibodies and neutralizing activity robustly reduced after 6 months of vaccination. Immunized mice demonstrated cellular response against Gamma and Zeta variants, and after viral infection, reduced viral loads, IL-6 expression, and histopathological outcome in the lungs. TNF levels were unchanged in immunized or not immunized mice after infection with the Gamma variant. Furthermore, serum neutralization activity rapidly increases after infection with the Gamma and Zeta variants. Our data suggest that immunization with inactivated WT SARS-CoV-2 induces a promptly responsive cross-reactive immunity response against the Gamma and Zeta variants, reducing COVID-19 pathological outcomes.
【저자키워드】 SARS-CoV-2, cross-protection, Gamma variant, Inactivated vaccine, Zeta variant, 【초록키워드】 COVID-19, Production, IgG, viral infection, immune response, vaccination, Immunity, IL-6, variant, Infection, immune system, outcome, immunization, variants, SARS-CoV-2 vaccine, Neutralizing activity, Viral, mice, Lungs, Gamma, circulation, viral variant, inactivated, Serum Neutralization, cellular response, TNF, antibody production, cross-reactive, follow-up study, individual, reduced viral loads, viral loads, vaccinated individuals, immunized mice, IL-6 expression, mice immunization, pathological outcomes, WT SARS-CoV-2, anti-S antibody, immunized, robust, produced, performed, significantly, addition, evaluated, conducted, reduced, increase, reducing, demonstrated, induce, evade, histopathological, levels of antibody, pathological outcome, 【제목키워드】 Gamma,