A Study of SII Yellow Fever Vaccine to Compare Safety and Immunogenicity With STAMARIL

The study is designed as a Phase III, double-blind, multicenter, randomized, active-controlled, parallel-group design in which two groups of participants will receive either SII-YFV or STAMARIL® - a licensed and WHO pre-qualified YFV. The study will start only after the approval from the applicable ethics committees and national regulatory agencies.

There will be three scheduled visits during the study. A screening and vaccination visit (Day 0) followed by additional study visits on Day 28 and on Day 180 post-vaccination. Throughout the study, participants/parent/guardian will be encouraged to contact the study team if the participant is unwell and the study team will additionally maintain contact with study participants. The participant or parent/guardian will be contacted telephonically on Day 90 to enquire about participant's health and occurrence of any serious adverse events (SAEs). Active surveillance for vaccine reactogenicity will be conducted in reactogenicity cohort from the time of vaccination (Day 0) until Day 10 following vaccination. Unsolicited AE will be collected from all study participants until Day 28 post vaccination. SAEs will be collected from all participants throughout the study (to Day 180).