Apply to trial NCT07050732

Immunogenicity of RSVPreF3 Vaccine in Immunocompromised Persons

This clinical trial is being done to learn more about how well a vaccine (Arexvy®) for respiratory syncytial virus, also known as RSV, works in people with weakened immune systems. The main questions it aims to answer are: * Does 1 or 2 doses of Arexvy work better in people with weakened immune systems? * What medical problems do participants have after receiving Arexvy? Participants with weakened immune systems will: * Receive 3 study vaccines over the course of 1 year * Keep a diary of symptoms for 7 days after each vaccine * Have 3 in-person follow up study visits for checkups and tests over the course of 1.5 years * Have 6 phone follow up study visits over the course of 1.5 years