Randomized, Double-Blind, Placebo-Controlled, Parallel-Group, Multi-Centre Phase II/III Adaptive Clinical Trial to Assess the Safety and Immunogenicity of Gam-COVID-Vac Combined Vector Vaccine for SARS-Сov-2 Infection in Indian Healthy Subjects.~In phase II trial, 100 subjects of immunogenicity group will be enrolled in 3:1 (Test:Placebo) ratio. These 100 subjects will be assessed for safety and immunogenicity outcomes till Day 28 post the first dose of investigational medicinal product (IMP)/placebo administration and will continue with study assessments till Day 180. Safety and immunogenicity data collected till Day 28 will be submitted to the regulatory authority for recommendation to proceed with Phase III recruitment.~In Phase III trial, 1500 subjects will be enrolled and randomized in the ratio of 3:1 (Gam-COVID--Vac : Placebo).~Each subject will participate in this adaptive study phase II/III clinical trial for 180±14 days after the first dose of the IMP/placebo and will have one screening visit and seven on-site visits during the trial period. The IMP/placebo will be administered intramuscularly during vaccination Visits 1 and 3 (Day 1 and Day 21±2). The observation Visits 2, 4, 5, 6, and 7 will be made on Day 19±2, Day 28±2, Day 42±2, Day 90±7, and Day 180±14, respectively. During the observation visits, vital indicators will be assessed in all subjects and changes in the subjects' condition and well being compared to the previous visit will be recorded. The schedule of examination procedures is mentioned in the Schedule of Event tables.~Additionally, the subjects will be able to have remote consultations with the study physician through the weekly telephonic follow-up.~Blood samples will be taken from immunogenicity group of phase II (all 100) and phase III (284 out of 1500) trials during the following visits to assess the immunogenicity parameters.
Randomized, Double-Blind, Placebo-Controlled, Parallel-Group, Multi-Centre Phase II/III Adaptive Clinical Trial to Assess the Safety and Immunogenicity of Gam-COVID-Vac Combined Vector Vaccine for SARS-Сov-2 Infection in Indian Healthy Subjects.