Evaluation of the Immunogenicity and Safety of Ad26.COV2.S's COVID-19 Vaccine

Phase II, non-randomized, open-label, comparative, national, multicenter trial in Mali, aimed to assess the humoral vaccine immune response induced by Ad26.COV2.S vaccine in 200 adults one month after receiving the complete vaccination schedule of SARS-CoV-2 vaccine.

The main objective of this phase II trial is to evaluate the humoral immune response induced by the Ad26.COV2.S vaccine in adults one month after complete vaccination regimen against SARS-CoV-2, compared younger (up to 45 years old) and elderly (55+ years old) populations. 200 participants will be included, 200 participants for each vacine. The age categories are 18 - 45 years, 55 - 64 years and 65+ years. The number of participants per age group will be distributed as follows 1:1:0,5. There will be no comparison between population on different vaccines. Ad26.COV2 vaccine (200 participants) 18-45 years old, 80 participants 55-64 years old, 80 participants 65 years old or older, 40 participants Participants in Ad26.COV2 arm receive intramuscularly as a single dose of 0.5mL. Humoral vaccine immune responses, induced by Ad26.COV2.S vaccine, will be measured by ELISA at D0, M1, M2, M6, M12 and M24.