Phase II, comparative, non-randomized trial assessing the immunogenicity and safety of vaccine candidate Moderna-1273 against SARS-CoV-2. A total of 180 volunteers will be included and vaccinated (2 doses, at day 1 and day 29), divided in 3 groups (60 volunteers 18 - 45 years old, 60 volunteers 65 - 74 years old, 60 volunteers at least 75 years old). Vaccinated volunteers of the three arms will be immune-monitored during 24 months via a battery of in vitro and ex vivo tests to comprehensively assess the course of humoral, cellular and mucosal immunity over time.
This study aims to evaluate the immunogenicity of Moderna mRNA-1273 vaccine in volunteers aged 65 years or more compared to volunteers aged 18-45 years, over 24 months duration. It will provide necessary data on the early immunological response to the vaccine and its evolution in quantitative and qualitative terms. This study will allow establishing how aging influences the response to the vaccine and help to adapt the vaccinal plan. For instance it will suggest the necessity of a vaccination booster.