Study of the Safety and Immune Response to Multiple Doses of Arexvy RSV Vaccine in Adults with Weakened Immune Systems

What this Trial Is About

Researchers are studying how well the vaccine Arexvy4, designed to protect against respiratory syncytial virus RSV, works in people with weakened immune systems. The trial aims to find out whether one or two doses of Arexvy provide better protection and to monitor any medical problems participants experience after vaccination. The study is a randomized, single-blind Phase 2 trial including immunocompromised adults and a small group of healthy comparators. Participants with weakened immune systems are randomly assigned to one of two groups one group receives a dose of Arexvy followed by a placebo vaccine 60 days later the other group receives two doses of Arexvy 60 days apart. Both groups get a booster dose of Arexvy one year after the first dose. A third group of healthy adults receives a single dose of Arexvy. The study vaccines are given over the course of one year. During the study, participants will keep a symptom diary for a week after each vaccine dose. They will also attend three in-person follow-up visits for checkups and tests over 1.5 years, plus six phone follow-ups during the same period. Researchers will measure immune responses to the vaccine, including antibody levels and T-cell activity, and monitor any side effects or adverse events. The main outcome is the immune response 30 days after each vaccine dose.

Immunogenicity of RSVPreF3 Vaccine in Immunocompromised Persons