1) Serious Adverse Events-SAE (It will measure as: -Occurrence of the SAE (Yes; No); - Duration (Time from start date until end date of event); -Description of the event; Result (Recovered; Recovered with squeals; Persists; Death; Unknown); - Causality (Causal association consistent with vaccination; Undetermined; Inconsistent causal association with vaccination; not classifiable). Measurement time: daily for 28 days after each dose. 2) Titer of specific anti-RBD IgG antibodies (Percentage of subjects with seroconversion 4 fold). Measurement time At baseline and; 14; 28 and; 56 days.

1) Serious Adverse Events-SAE (It will measure as: -Occurrence of the SAE (Yes; No); - Duration (Time from start date until end date of event); -Description of the event; Result (Recovered; Recovered with squeals; Persists; Death; Unknown); - Causality (Causal association consistent with vaccination; Undetermined; Inconsistent causal association with vaccination; not classifiable). Measurement time: daily for 28 days after each dose. 2) Titer of specific anti-RBD IgG antibodies (Percentage of subjects with seroconversion 4 fold). Measurement time At baseline and; 14; 28 and; 56 days.