An Extension and Crossover Vaccination Study on the Immune Response and Safety of a Vaccine Against Respiratory Syncytial Virus Given to Adults 60 Years of Age and Above Who Participated in RSV OA=ADJ-006 Study

The purpose of this study is: * To investigate the optimal timing for revaccination after the initial RSVPreF3 OA vaccine dose, * To evaluate the long-term immune persistence and safety up to 5 consecutive RSV seasons (approximately 60 months) of a single dose of RSVPreF3 OA vaccine, * To give the opportunity to participants who received only placebo in the RSVOA=ADJ- 006 study, to receive a dose of the RSVPreF3 OA vaccine and collect additional safety information.