To assess the safety; tolerability and reactogenicity profile of the candidate vaccine ChAdOx1 nCoV;To assess efficacy of the candidate ChAdOx1 nCoV-19 against severe and non-severe COVID-19;To assess the safety; tolerability and reactogenicity profile of the candidate vaccine ChAdOx1 nCoV in people living with HIV;To assess cellular and humoral immunogenicity of ChAdOx1 nCoV-19 in people living with HIV after one and two doses of vaccine

To assess the safety; tolerability and reactogenicity profile of the candidate vaccine ChAdOx1 nCoV;To assess efficacy of the candidate ChAdOx1 nCoV-19 against severe and non-severe COVID-19;To assess the safety; tolerability and reactogenicity profile of the candidate vaccine ChAdOx1 nCoV in people living with HIV;To assess cellular and humoral immunogenicity of ChAdOx1 nCoV-19 in people living with HIV after one and two doses of vaccine