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 the requirements of the protocol (e.g., completion of the diary cards, attend regular phone calls/study site visits, perform self-swabbing (study participants in China only), ability to access and utilize a phone or other electronic communications).
• Participants who are medically stable in the opinion of the investigator at the time of vaccination. 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 if considered by the investigator as medically stable.
• Written or witnessed informed consent obtained from the participant (participant must be able to understand the informed consent) prior to performance of any study specific procedure.

Exclusion Criteria

Medical Conditions:

• History of any reaction or hypersensitivity likely to be exacerbated by any component of the study intervention(s).
• Any clinical conditions for which serum samples would be prohibited for transfer to local central lab for testing. These clinical conditions include hepatitis B, hepatitis C, HIV and Syphilis based on medical history and physical examination (all participants) and laboratory screening tests (overseas participants).
• Any confirmed or suspected immunosuppressive or immunodeficient condition resulting from disease (e.g., current malignancy, human immunodeficiency virus) or immunosuppressive/cytotoxic therapy (e.g., medication used during cancer chemotherapy, organ transplantation, or to treat autoimmune disorders), based on medical history and physical examination (no laboratory testing required).
• Any history of dementia or any medical condition that moderately or severely impairs cognition.
• Recurrent history or uncontrolled neurological disorders or seizures. Participants with medically controlled active or chronic neurological diseases can be enrolled in the study as per investigator assessment, provided that their condition will allow them to comply with the requirements of the protocol (e.g. completion of the diary cards, attend regular phone calls/study site visits, perform self-swabbing (study participants in China only).
• Significant underlying illness that in the opinion of the investigator would be expected to prevent completion of the study (e.g., life-threatening disease likely to limit survival to less than 1 year).
• Serious or unstable chronic illness.
• Any other clinical condition that, in the opinion of the investigator, might pose additional 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 invasive medical device) other than the study intervention(s) during the period beginning 30 days before the dose of study intervention(s), or their planned use during the study period.
• Planned or actual administration of a vaccine not foreseen by the study protocol in the period starting 30 days before and ending 30 days after study intervention administration, with the exception of COVID-19 and inactivated/subunit influenza vaccines which can be administered up to 14 days before or from 14 days after each study intervention.
• Administration of long-acting immune-modifying drugs or planned administration at any time during the study period (e.g., infliximab).
• Administration of immunoglobulins and/or any blood products or plasma derivatives during the period starting 90 days before the study intervention administration or planned administration during the study period.
• Chronic administration (defined as more than 14 consecutive days in total) of immunosuppressants or other immune-modifying drugs during the per