With the ongoing SARS-CoV-2 pandemic, the safety and efficacy of vaccine prophylaxis with new vaccines have become vital.

OBJECTIVE

To study tolerability and efficacy of the Gam-COVID-Vac (Sputnik V) vaccine in the short term in a real-world setting in the example of the Federal remote consulting center on vaccination against new coronavirus infection COVID-19 of National Medical Research Center for Therapy and Preventive Medicine.

MATERIALS AND METHODS

We retrospectively analyzed data from the registration cards of the first 500 voluntary vaccination recipients who received two vaccine doses in October-December 2020. Serum immunoglobulin (Ig) M and G levels to SARS-CoV-2 were measured in 204 participants at baseline, at Day 21, and at Day 42 after the injection of component I of Gam-COVID-Vac vaccine. Test for SARS-CoV-2 coronavirus RNA in a nasopharyngeal and/or oropharyngeal mucosa smear was performed before injection of component I of the vaccine using real-time PCR method on a DT-96 amplifier (DNA-Technology, Russia) using SARS-CoV-2/SARS-CoV reagent kit (DNA-Technology, Russia). Anti-SARS-CoV-2 IgG and IgM were measured using reagent kits for enzyme immunoassay (Vector-Best, Russia).

RESULTS

During the follow-up (42 days), none of the vaccine recipients experienced serious adverse events. During the first 14 days after receiving component I of the vaccine Gam-COVID-Vac, eight vaccine recipients got sick with COVID-19; the disease had a mild course and did not require hospital admission. On Day 21, no IgM antibodies were detected in any of the vaccine recipients, while the IgG level was detectable and the cutoff index (CI) was 11.3 [3.4; 16.2]. On Day 42 after the injection of component I of the Gam-COVID-Vac vaccine, there was an increase in IgG levels, and CI was 16.2 [16.0; 16.4] in most subjects, while no IgM levels were detected in any of the vaccine recipients tested.

CONCLUSION

The data obtained may indicate a favorable tolerability and safety profile of the combined vector vaccine Gam-COVID-Vac, as well as short-term efficacy, according to the change of anti-SARS-CoV-2 IgG and absence of severe COVID-19 disease in vaccinated subjects during the follow-up period. To obtain further evidence of the long-term clinical efficacy of Gam-COVID-Vac, follow-up of vaccinated subjects should be continued.