• Male or female participants who were previously enrolled in the RSV OA=ADJ-006 study and received placebo (Placebo group) or a single dose of the RSVPreF3 OA vaccine (RSV\_1dose group).

• Participants who, in the opinion of the investigator, can and will comply with the requirements of the protocol (e.g. completion of the diary cards, attend regular phone calls/study site visits, ability to access and utilize a phone or other electronic communications).

• Written or witnessed informed consent obtained from the participant prior to performance of any study specific procedure.

• Participants who are medically stable in the opinion of the investigator at study entry. Participants with chronic stable medical conditions with or without specific treatment, such as diabetes, hypertension or cardiac disease, are allowed to participate in this study.