Yesterday Moderna reported that its respiratory syncytial virus (RSV) vaccine, mResvia, showed only 50% efficacy in preventing the illness after 18 months. The results are disappointing compared to the 81% efficacy seen at 3.7 months.
Moderna’s vaccine also underperformed compared to GlaxoSmithKlein’s vaccine, Arexvy, which was 68% effective over 23.3 months in a clinical trial. Trials have shown Pfizer's Abrysvo to be 78% effective after 16.4 months.
The drugmaker announced the findings late yesterday afternoon at a meeting of the Centers for Disease Control and Prevention's (CDC's) Advisory Committee on Immunization Practices (ACIP).
Last month the Food and Drug Administration (FDA) approved the Moderna vaccine for use in older adults, making it the second approved RSV vaccine for adults 60 years and older. ACIP currently recommends all US adults 75 and older receive a single RSV vaccine, and that people ages 60 to 74 also receive a dose of the vaccine.
According to the CDC, 60,000 to 160,000 older adults each year are hospitalized in the United States due to RSV.
Currently the CDC and ACIP are weighing age recommendations for approved RSV vaccines given concerns about the risk of Guillain-Barre syndrome (GBS) following RSV vaccination.