RSV Immunogenicity Study in the Elderly (RISE)

Inclusion Criteria: * Male or female individuals who were born between 1965 and 1960 or 1945 and before, at the time of the first vaccination, who live in the community or in a long-term care facility. * Individuals who can understand and read Swedish. * Individuals who can provide written consent and agree (by written consent) to receive the Arexvy vaccine. * Participants who, in the opinion of the investigator, can and will comply with the requirements of the protocol. * Participants who are medically stable in the opinion of the investigator at the time of first vaccination. * Participants with chronic stable medical conditions with or without specific treatment, such as diabetes, hypertension or cardiac disease, are allowed to participate if considered by the investigator as medically stable. Exclusion Criteria: * Individuals who are medically immunocompromised, less than 2 years since hematopoietic stem cell transplantation (HSCT) or graft-versus-host disease (GVHD), solid-organ transplanted, using immunosuppressive drugs for treatment of cancer and who have inflammatory mediated or autoimmune conditions, as judged by the Investigator. * Individuals who have already received an RSV vaccine dose at any time in the past. * Any known or suspected reaction, hypersensitivity or allergies to be exacerbated by any product or component included in the vaccine and trial. * Mental inability, reluctance or language difficulties that result in difficulty understanding the meaning of participation in the trial. * Treatment or disease which, according to the investigator, can affect treatment or trial results. * Any of the following medical conditions: 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, History of chronic alcohol consumption and/or drug abuse as deemed by the investigator to render the potential participant unable/unlikely to provide accurate safety reports or comply with study procedures. * Participation in another clinical trial during the study period, or any previous clinical trials with RSV- or hMPV-vaccine or other prophylaxis. * Planned move during the study period that will prohibit participating in the study until study end. * Participation of any study personnel or their immediate dependents, family or household members as well as any family relations to Sponsor or PI. * Co-administration of other vaccines less than 14 days before or after study vaccination. A period of less than 30 days before or after study vaccination applies in the case of Shingrix.