Safety and reactogenicity measured as: 1. Solicited local reactogenicity signs and symptoms for 7 days following vaccination measured using participant symptom diary entries 2. Solicited systemic reactogenicity signs and symptoms for 7 days following vaccination measured using participant symptom diary entries 3. Unsolicited adverse events (AEs) for 28 days following vaccination measured using participant symptom diary entries 4. Safety laboratory measures measured using routine Haematology and Biochemistry at day 0; 3; 7 and 42 5. Occurrence of disease enhancement episodes measured using surveillance for COVID-19 hospitalisations during the whole study period

Safety and reactogenicity measured as: 1. Solicited local reactogenicity signs and symptoms for 7 days following vaccination measured using participant symptom diary entries 2. Solicited systemic reactogenicity signs and symptoms for 7 days following vaccination measured using participant symptom diary entries 3. Unsolicited adverse events (AEs) for 28 days following vaccination measured using participant symptom diary entries 4. Safety laboratory measures measured using routine Haematology and Biochemistry at day 0; 3; 7 and 42 5. Occurrence of disease enhancement episodes measured using surveillance for COVID-19 hospitalisations during the whole study period