Overall of 110 volunteers aged 18 to 60 should be screened taking into account possible early departure from the study. It is supposed that 100 subjects will complete all screening procedures and will be randomized in a 3:1 ratio into two groups: a control group (using placebo, 25 subjects) and a study group (using Gam-COVID-Vac Combined Vector Vaccine to Prevent Coronavirus Infection Caused by SARS-CoV-2, 75 subjects).~The duration of participation in the study for one subject will be 180±14 days after the first dose of IMP/placebo, during which each subject will undergo a screening visit and five face-to-face visits to the doctor-researcher. Intramuscular injection of IMP or placebo will be carried out on vaccination visits N 1 and N 2 (Day 0 and Day 21±2). Further observation visits No 3, 4, 5 will be conducted on days 28±2, 42±2 and 180±14 respectively. It is allowed to conduct observation visits No. 3, 4 via telephone contact (TC). During the monitoring visits, all subjects of the study will be assessed on key vital indicators and data will be collected on changes in the status and well-being of the subjects since the previous visit.~The duration of participation in the study for one subject will be 180±14 days after the first dose of IMP/placebo, during which each subject will undergo a screening visit and five observation visits. Intramuscular injection of IMP or placebo will be carried out on vaccination visits N 1 and N 2 (Day 0 and Day 21±2). Further observation visits No 3, 4, 5 will be conducted on days 28±2, 42±2 and 180±14 respectively.
Randomized, double-blind (blinded for the trial subject and the study physician), placebo controlled, multi-center clinical trial in parallel assignment of efficacy, immunogenicity, and safety of the Gam-COVID-Vac combined vector vaccine against the SARS-CoV-2-induced coronavirus infection in adults in the SARS-СoV-2 infection prophylactic treatment.