A Study on the Immune Response, Safety and the Occurrence of Respiratory Syncytial Virus (RSV)-Associated Respiratory Tract Illness After Administration of RSV OA Vaccine in Adults 60 Years and Older

Inclusion Criteria:

• Adult male or female of ≥60 YOA at the time of study intervention administration,who live in the community dwelling (CD participants).

• Participants who, in the opinion of the investigator, can and will comply with therequirements of the protocol (e.g., completion of the diary cards, attend regularphone calls/study site visits, perform self-swabbing (study participants in Chinaonly), ability to access and utilize a phone or other electronic communications).

• Participants who are medically stable in the opinion of the investigator at the timeof vaccination. Participants with chronic stable medical conditions with or withoutspecific treatment, such as diabetes, hypertension or cardiac disease, are allowedto participate in this study if considered by the investigator as medically stable.

• Written or witnessed informed consent obtained from the participant (participantmust be able to understand the informed consent) prior to performance of any studyspecific procedure.

Exclusion Criteria:

Medical Conditions:

• History of any reaction or hypersensitivity likely to be exacerbated by anycomponent of the study intervention(s).

• Any clinical conditions for which serum samples would be prohibited for transfer tolocal central lab for testing. These clinical conditions include hepatitis B,hepatitis C, HIV and Syphilis based on medical history and physical examination (allparticipants) and laboratory screening tests (overseas participants).

• Any confirmed or suspected immunosuppressive or immunodeficient condition resultingfrom disease (e.g., current malignancy, human immunodeficiency virus) orimmunosuppressive/cytotoxic therapy (e.g., medication used during cancerchemotherapy, organ transplantation, or to treat autoimmune disorders), based onmedical history and physical examination (no laboratory testing required).

• Any history of dementia or any medical condition that moderately or severely impairscognition.

• Recurrent history or uncontrolled neurological disorders or seizures. Participantswith medically controlled active or chronic neurological diseases can be enrolled inthe study as per investigator assessment, provided that their condition will allowthem to comply with the requirements of the protocol (e.g. completion of the diarycards, attend regular phone calls/study site visits, perform self-swabbing (studyparticipants in China only).

• Significant underlying illness that in the opinion of the investigator would beexpected to prevent completion of the study (e.g., life-threatening disease likelyto limit survival to less than 1 year).

• Serious or unstable chronic illness.

• Any other clinical condition that, in the opinion of the investigator, might poseadditional risk to the participant due to participation in the study.

Prior/Concomitant Therapy:

• Previous vaccination with RSV vaccine.

• Use of any investigational or non-registered product (drug, vaccine or invasivemedical device) other than the study intervention(s) during the period beginning 30days before the dose of study intervention(s), or their planned use during the studyperiod.

• Planned or actual administration of a vaccine not foreseen by the study protocol inthe period starting 30 days before and ending 30 days after study interventionadministration, with the exception of COVID-19 and inactivated/subunit influenzavaccines which can be administered up to 14 days before or from 14 days after eachstudy intervention.

• Administration of long-acting immune-modifying drugs or planned administration atany time during the study period (e.g., infliximab).

• Administration of immunoglobulins and/or any blood products or plasma derivativesduring the period starting 90 days before the study intervention administration orplanned administration during the study period.

• Chronic administration (defined as more than 14 consecutive days in total) ofimmunosuppressants or other immune-modifying drugs during the period starting 90days prior to the study intervention administration or planned administration duringthe study period. For corticosteroids, this will mean prednisone >=20 mg/day, orequivalent. Inhaled and topical steroids are allowed.

Prior/Concurrent Clinical Study Experience:

• Concurrently participating in another clinical study, at any time during the study period, in which the participant has been or will be exposed to an investigational or a non-investigational intervention (drug/invasive medical device).

Other Exclusion Criteria:

• History of chronic alcohol consumption and/or drug abuse as deemed by theinvestigator to render the potential participant unable/unlikely to provide accuratesafety reports or comply with study procedures.

• Bedridden participants.

• Planned move during the study conduct that prohibits participation until study end.

• Participation of any study personnel or their immediate dependents, family, orhousehold members.