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.~The trial will include 40,000 volunteers aged 18+. After screening, they will be randomized (3:1) into two groups - a reference group of 10,000 volunteers receiving placebo and a study group of 30,000 volunteers receiving the Gam-COVID-Vac combined vector vaccine against the SARS-СoV-2-induced coronavirus infection.~The trial subjects will be randomized into five age strata: 18-30, 31-40, 41-50, 51-60, and 60+ years.~The PCR test for SARS-CoV-2 RNA detection at the visit is performed during screening and before the second administration of the vaccine/placebo~Each subject will participate in the trial for 180±14 days after the first dose of the study drug/placebo and will have one screening visit and five on-site visits to the study physician during the said period. The study drug/placebo will be administered intramuscularly during vaccination visits 1 and 2 (day 0 and day 21±2). Subsequent observation visits 3, 4, and 5 will be made on days14±2, 28±2, 35±2,42±2, and 180±14 respectively. During the observation visits, vital signs will be assessed in all trial subjects and changes in the subjects' condition and wellbeing compared to the previous visit will be recorded. Observation visits may be remote, through the telemedicine consultation (TMC).~Additionally, the trial subjects will be able to have remote consultations with the physician through the TMC.~Blood samples will be taken from certain subjects during the following visits to assess the immunogenicity parameters listed below:~Virus-neutralizing activity (300 subjects) ×3 Interferon gamma (107 subjects) ×3 CD4 and CD8 cell count and ratio (50 subjects) SARS-CoV-2 glycoprotein-specific antibodies titer (9,520 subjects) ×3 Determination of the titer of SARS-CoV-2 nucleocleocapsid protein-specific antibodies(9,520 subjects) ×3~Blood sampling will be performed on the day of injecting the first dose of the study drug/placebo immediately prior to the study drug administration Blood sampling for immunogenicity parameters assessment will be only carried out in specially selected study centers.~Blood samples will be taken from 9,520 trial subjects. All four immunogenicity parameters may be assessed in one trial subject.~Trial subjects data will be collected using electronic case report forms and electronic questionnaires to be filled by trial subjects.
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.