A Study Evaluating Persistence of the Immune Response of the Adjuvanted Respiratory Syncytial Virus (RSV) Vaccine and the Safety and Immune Response Following Revaccination in Adults 18 Years of Age and Above Who Received Lung or Kidney Transplant

This study is looking for adults aged 18 or older who have had a lung or kidney transplant. You must have already taken part in a specific previous study (called RSV OA=ADJ-023) where you received one or two doses of the RSV vaccine being tested.

It's important that your transplant happened more than a year ago, and you must be taking regular medication to prevent your body from rejecting the new organ. For kidney transplant patients, your kidney function needs to be stable. For lung transplant patients, your lung function also needs to be stable. You should also be able to attend all study visits and follow the study instructions carefully.

If you are a woman, you can join if you are past menopause, have had certain operations (like removal of ovaries or womb), or if you are able to use effective birth control during and for a month after the study, and have a negative pregnancy test before starting.

If you join this study, you will receive an additional dose of the RSV vaccine. You will need to attend appointments for blood tests, which allow the researchers to check your immune response and how long the vaccine's protection lasts. You will also be asked about any new health problems, to monitor how safe the vaccine is for you. Throughout the study, you may need to complete diary cards or use a phone for communication. The exact number of visits and the total length of your participation will be explained in detail by the study team, typically involving several follow-up visits over a period of time after vaccination.