A. To assess the safety; tolerability and reactogenicity profile of the candidate vaccine ChAdOx1nCoV-19 1. Occurrence of serious adverse events (SAEs) throughout the study duration2. Occurrence of solicited local and systemic reactogenicity signs and symptoms for 7 days following vaccination3. Occurrence of unsolicited adverse events (AEs) at all scheduled visits;4. Change from baseline for safety laboratory measures and; 5. Occurrence of SAE of special interest: disease enhancement episodesB. To assess immunogenicity of ChAdOx1 nCoV-191. ELISA to quantify IgG antibodies against SARSCoV-2 spike protein (seroconversion rates)

A. To assess the safety; tolerability and reactogenicity profile of the candidate vaccine ChAdOx1nCoV-19 1. Occurrence of serious adverse events (SAEs) throughout the study duration2. Occurrence of solicited local and systemic reactogenicity signs and symptoms for 7 days following vaccination3. Occurrence of unsolicited adverse events (AEs) at all scheduled visits;4. Change from baseline for safety laboratory measures and; 5. Occurrence of SAE of special interest: disease enhancement episodesB. To assess immunogenicity of ChAdOx1 nCoV-191. ELISA to quantify IgG antibodies against SARSCoV-2 spike protein (seroconversion rates)