The article presents the results of a study of the immunogenicity and reactogenicity of the vaccine Gam-COVID-Vac (Sputnik V) when used in military personnel undergoing military service on conscription. From 300 military personnel consistently vaccinated with one and two components of Gam-COVID-Vac at the intervals of 21 days, blood serum was obtained and examined three times: before vaccination, and 30 and 60 days after the introduction of the first component of the vaccine. In the blood serums, the content of Class G antibodies to the SARS-CoV-2 was determined by the method of solid-phase enzyme immunoassay. After immunization with the Gam-COVID-Vac vaccine, the average geometric titer of Class G antibodies to SARS-CoV-2 -in the blood serum of a military personnel obtained during the second and third examinations (5.02 log2 and 5.67 log2) increased by 2.4 and 2.7 times, respectively (p 0.05), compared to the same indicator before the vaccination (2.11 log2). Total of 30 days after the introduction of the first component of the vaccine (Nine days after the introduction of the second component of the vaccine), Class G antibodies to the new coronavirus SARS-CoV-2 were detected in the 86.7% of military personnel, and after 60 days in 92% of vaccinated. Studies have revealed moderate reactogenicity of the vaccine. Moreover, the proportion of postvaccination reactions in the first 35 days after the introduction of the second component of the vaccine was less after the introduction of the first component of the vaccine. So, if after the introduction of the first component of the vaccine, an increase in body temperature 37 C was observed in 20% of military personnel, then after the introduction of the second component only in 9%, and the share of local reactions decreased from 94%. There have been no cases of serious adverse events after immunization of military personnel with the Gam-COVID-Vac vaccine.