1. Percentage of serious adverse events related to the investigational product (Adverse events classified as serious with a causal association consistent with vaccination according to the Cuban vaccine pharmacovigilance system). Measurement time: up to 28 days after the third dose.2. Proportion of subjects with seroconversion of SARS-CoV-2 anti-RBD IgG antibodies (Considering seroconversion as = 4 times the initial determination of the antibody titer). Measurement time: day 56.

1. Percentage of serious adverse events related to the investigational product (Adverse events classified as serious with a causal association consistent with vaccination according to the Cuban vaccine pharmacovigilance system). Measurement time: up to 28 days after the third dose.2. Proportion of subjects with seroconversion of SARS-CoV-2 anti-RBD IgG antibodies (Considering seroconversion as = 4 times the initial determination of the antibody titer). Measurement time: day 56.