Primary Endpoints: 1. Proportion of study subjects with active COVID-19 disease developed 21±2 days after vaccination with the Sputnik-Light vector vaccine as compared with placebo2. Incidence and severity of adverse events in trial subjects:a. Incidence of local and systemic reactions to the vaccine in 7 days after injection with vaccine/placebob. Incidence and severity of AEs and SAEs over the course of subject’s participation in the study

Primary Endpoints: 1. Proportion of study subjects with active COVID-19 disease developed 21±2 days after vaccination with the Sputnik-Light vector vaccine as compared with placebo2. Incidence and severity of adverse events in trial subjects:a. Incidence of local and systemic reactions to the vaccine in 7 days after injection with vaccine/placebob. Incidence and severity of AEs and SAEs over the course of subject’s participation in the study