Vaccines SputnikV and Sinopharm against COVID-19: comparative research of immunogenicity and reactogenicity

In 2020–2021, a group of researchers from Gomel State Medical University conducted a prospective comparative clinical research that clearly demonstrates the differences in immunogenicity and reactogenicity of Sputnik V and Sinopharm. In equal groups, the humoral immune response and the safety profile of vaccines were assessed with analysis points at 42 days and 6 months after vaccination. Serological status was assessed before vaccination in all participants, followed by analysis in seronegative and seropositive groups. As part of the study, higher immunogenicity of the Sputnik V vaccine (Gam-COVID-Vac) were established at all points of analysis. IgG levels in vaccinated individuals who had previously recovered from SARS-CoV-2 infection (“hybrid immunity”) were higher than in individuals not previously infected with SARS-CoV-2. Reactions to studied vaccines were only mild and moderate, while the lower reactogenicity, namely, the lower frequency of fever, was expectedly demonstrated in the inactivated Sinopharm vaccine group. The levels of IgG in the seropositive...