Moderna’s mRNA RSV Vaccine's Protection Wanes

With a third respiratory syncytial virus (RSV) vaccine approved by the U.S. FDA, many people ask which one offers the best protection from disease. With the 2024-2025 RSV season fast approaching, the U.S. CDC's recent vaccine meeting helped answer questions.

Moderna's presentation on June 26, 2024, to the CDC’s Advisory Committee on Immunization Practices, led by Rituparna Das, MD, PhD, disclosed that mRESVIA® (mRNA-1345) showed about 81% efficacy after 3.7 months, but around 50% (37.5%, 60.7%) efficacy in preventing illness after 18 months.

Additionally, Moderna stated that the RSV vaccine is generally well tolerated in over 19,700 adults over 60 years old vaccinated with a 50g licensed dose and that there are no safety concerns.

mRESVIA is an RSV vaccine containing an mRNA sequence encoding a stabilized prefusion F glycoprotein. It uses the same lipid nanoparticles as Moderna's other approved vaccine.

As of May 2024, an estimated 24.4% (95% Confidence Interval: 23.7%-25.2%) of adults 60 years and older reported receiving an RSV vaccine during the last RSV season.