Phase I: 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. Phase II: Concentration of specific anti-RBD IgG antibodies (Percentage of subjects with seroconversion 4-fold to pre-vaccination). Measurement time: Day 0; 42 and 70

Phase I: 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. Phase II: Concentration of specific anti-RBD IgG antibodies (Percentage of subjects with seroconversion 4-fold to pre-vaccination). Measurement time: Day 0; 42 and 70