The first phase will enroll 10,000 persons initiating vaccination (assuming 4 vaccines). If more vaccines become available additional 2,500 persons per vaccine will be included. Subsequent phases with larger sections of the population included may be implemented.

Participants will have 6 study visits and be followed for 2 years after the first vaccination, which offers the participants an extra close follow-up on vaccine effectiveness.

Safety data will be collected at study visits until 3 months after the first vaccination. Research samples will be collected at each study visit during the two-year follow-up