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

Eligibility Criteria

• * 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.
• * Any confirmed or suspected immunosuppressive or immunodeficient condition resulting from disease or immunosuppressive/cytotoxic therapy based on medical history and physical examination.
• * History of any reaction or hypersensitivity likely to be exacerbated by any component of the study intervention.
• * Hypersensitivity to latex.
• * Serious or unstable chronic illness.
• * Recurrent or un-controlled neurological disorders or seizures.
• * Significant underlying illness that in the opinion of the investigator would be expected to prevent completion of the study.
• * Any other medical condition that in the judgment of the investigator would make intramuscular injection unsafe.
• * Any other clinical condition that, in the opinion of the investigator, might pose additional risk to the participant due to participation in the study.
• * Any history of dementia or any medical condition that moderately or severely impairs cognition and understanding of the informed consent form and/or study procedures.
• * Participants who experienced an SAE or pIMD from first study intervention administration in the RSV OA=ADJ-006 study until enrollment in this study that was considered to be possibly or probably related to the study vaccine or non-study concomitant vaccines, either by the investigator or the sponsor, including hypersensitivity reactions.
• * Participants with a new onset of a pIMD or exacerbation of a pIMD from first study intervention administration in the RSV OA=ADJ-006 study until enrollment in this study, that, in the opinion of the investigator, exposes the participant to unacceptable risk from subsequent vaccination.