Best RSV Vaccination Launch Ever

As the three-day Advisory Committee on Immunization Practices (ACIP) meeting ended today, the morning session focused on Respiratory syncytial virus (RSV), the leading cause of hospitalization among U.S. infants.

Led by Sarah S. Long, MD, the Maternal/Pediatric RSV Work Group presentations included the summary of the effectiveness of Beyfortus™ (nirsevimab) in infants.

Beyfortus is a single-dose, extended half-life monoclonal antibody (mAb) that offers passive immunization to prevent lower respiratory tract infections. It has been approved by the U.S. FDA and other health agencies. 

On June 28, 2024, Amanda Payne, PhD, MPH, stated that Beyfortus was about 80% effective against RSV-associated encounters and hospitalizations among infants in their first RSV season during the 2023-2024 RSV season.

Furthermore, the U.S. CDC's RSVVaxView recently reported that among females with a young infant, over 43% reported that their infant received Beyfortus. 

The ACIP group, which comprises vaccine experts, loudly expressed its enthusiasm for the effectiveness and uptake of this first-year mAb therapy.

The group's primary concern was product availability for the 2024-2025 RSV season.

While Beyfortus was available in the U.S. for the 2023-2024 RSV season, demand quickly outstripped supply.

Beyfortus's producers, Sanofi and AstraZeneca, confirmed on May 2, 2024, that the expansion of the manufacturing network is progressing. In late 2024, the companies could have more than tripled their manufacturing capacity and increased mAb supply.

Of note, should Beyfortus production fall behind demand during the next RSV season, the U.S. FDA has approved a vaccine that pregnant women can receive, which enables antibodies to be passed to the unborn child.