Pfizer announced on Monday that its respiratory syncytial virus (RSV) vaccine, Abrysvo, elicited a robust immune response in a late-stage study involving four groups of adults aged 18 and above with compromised immune systems. According to Pfizer, a single 120 microgram dose of Abrysvo effectively produced strong neutralizing antibodies against both RSV subtypes, RSV-A and RSV-B, across all study groups. The vaccine was well-tolerated and exhibited a safety profile consistent with previous studies. Pfizer intends to submit the data to regulatory agencies for review.
The study evaluated two doses of Abrysvo in 203 adults divided into four groups: those with lung cancer, end-stage kidney disease, autoimmune inflammatory disorders, and solid organ transplant recipients, all of whom have compromised immunity and are at high risk of severe RSV-associated disease. Currently, Pfizer's vaccine is approved for individuals aged 60 and older and for use in women during the third trimester of pregnancy to protect newborns. RSV typically manifests as cold-like symptoms but is a major cause of pneumonia in young children and elderly adults, resulting in approximately 177,000 hospitalizations and 14,000 deaths annually in the United States.