Dose 1 Period will be conducted in 2 parts: Part 1: Participants in RSVPreF3 groups will receive lots 1, 2 and 3 of the investigational vaccine before Season 1. Part 2: Will be initiated when the vaccine lots in part 1 are exhausted at the study sites and participants in RSVPreF3 group will receive lot 4 of the investigational vaccine before Season 1.
This study will evaluate the efficacy of the RSVPreF3 OA investigational vaccine in preventing Lower Respiratory Tract Disease (LRTD) caused by RSV in adults ≥60 years of age following a single dose of the RSVPreF3 OA vaccine and following annual revaccination doses in Northern Hemisphere (NH) and in Southern Hemisphere (SH). This study will also assess if the vaccine is safe and induces an immune response.