In the phase 1/2 trial, the ChAdOx1 nCoV-19 vaccine (a chimpanzee adenovirus vector) was administered as a single intramuscular injection to the deltoid area at a dose of $5 imes 10^{10}$ viral particles. Participants were recruited into four groups, with blood drawn from all of them:

• Group 1: Received the vaccine only, with early follow-up visits.
• Group 2: Had higher blood volumes drawn to assess humoral and cellular immunogenicity.
• Group 3: Consisted of 10 participants who received a booster after the first dose, with follow-ups similar to Group 1.

Additionally, paracetamol was administered at two out of the five trial sites before and after vaccination to manage vaccine-associated reactions.