US FDA approves ABRYSVO, Pfizer’s maternal RSV vaccine for infants

Pfizer announced that the US Food and Drug Administration (FDA) has approved ABRYSVO (Respiratory Syncytial Virus Vaccine), the company’s bivalent RSV prefusion F (RSVpreF) vaccine, for the prevention of LRTD and severe LRTD caused by RSV in infants from birth up to six months of age by active immunisation of pregnant individuals at 32 through 36 weeks gestational age. ABRYSVO is unadjuvanted and composed of two preF proteins selected to optimise protection against RSV A and B strains and was observed to be safe and effective.

“ABRYSVO’s approval as the first and only maternal immunisation to help protect newborns immediately at birth through six months from RSV marks a significant milestone for the scientific community and for public health,” said Dr Annaliesa Anderson, Senior VP and CSO, Vaccine Research and Development, Pfizer.

The FDA’s decision is based on the data from the Phase 3 clinical trial (NCT04424316) MATISSE (Maternal Immunization Study for Safety and Efficacy), a randomised, double-blinded, placebo-controlled Phase 3 study designed to evaluate the efficacy, safety, and immunogenicity of the vaccine against LRTD and severe LRTD due to RSV in infants born to healthy individuals vaccinated during pregnancy. These results were published in The New England Journal of Medicine in April 2023.