1. Virologically confirmed symptomatic infection of Covid-19 (Yes/No). Measurement time: from 14 days after the administration of the third dose of CIGB-66; for 4 months. 2. Confirmed Covid-19 infection with signs of severe systemic disease (Yes/No). Measurement time: from 14 days after the administration of the third dose of CIGB-66; for 4 months. 3. Confirmed SARS-Cov-2 infection from routine surveillance (Yes/No). Measurement time: from 14 days after the administration of the third dose of CIGB-66; for 4 months. 4. Death from causes directly attributable to a complication of COVID-19 (Yes No). Measurement time: from 14 days after the administration of the third dose of CIGB-66; for 4 months. 5. Global burden of incidence: Cumulative incidence of cases in the observation period. Measurement time: from 14 days after the administration of the third dose of CIGB-66; for 4 months.

1. Virologically confirmed symptomatic infection of Covid-19 (Yes/No). Measurement time: from 14 days after the administration of the third dose of CIGB-66; for 4 months. 2. Confirmed Covid-19 infection with signs of severe systemic disease (Yes/No). Measurement time: from 14 days after the administration of the third dose of CIGB-66; for 4 months. 3. Confirmed SARS-Cov-2 infection from routine surveillance (Yes/No). Measurement time: from 14 days after the administration of the third dose of CIGB-66; for 4 months. 4. Death from causes directly attributable to a complication of COVID-19 (Yes No). Measurement time: from 14 days after the administration of the third dose of CIGB-66; for 4 months. 5. Global burden of incidence: Cumulative incidence of cases in the observation period. Measurement time: from 14 days after the administration of the third dose of CIGB-66; for 4 months.