The FDA has mandated that the manufacturers of the RSV vaccines, Abrysvo and Arexvy, incorporate a new warning on their labels highlighting the potential risk of Guillain-Barré Syndrome following vaccination.
Abrysvo, produced by Pfizer Inc. (PFE), and Arexvy, developed by GlaxoSmithKline Biologicals, received approval in May 2023. Postmarketing observational studies have indicated a heightened risk of Guillain-Barré Syndrome within 42 days post-vaccination with either vaccine. Nevertheless, the FDA has emphasized that the advantages of receiving the Abrysvo and Arexvy vaccines continue to surpass the associated risks.
Guillain-Barré Syndrome (pronounced gee-YAH-buh-RAY) is a rare condition where the body's immune system mistakenly attacks nerve cells, leading to muscle weakness and potentially even paralysis.
Respiratory syncytial virus (RSV) is a viral agent responsible for serious lung infections, such as bronchiolitis (infection of the small airways in the lungs) and pneumonia. It can cause acute lower respiratory tract infections (LRTI) in children under 5 years old and upper respiratory tract infections in adults. However, for elderly individuals, those with compromised immune systems, and patients with existing heart or lung conditions, RSV can result in life-threatening lower respiratory tract infections.
In financial terms, Pfizer's Abrysvo saw sales of $356 million during the third quarter of 2024, a decline from $375 million reported in the corresponding period the previous year. In contrast, GlaxoSmithKline's Arexvy recorded sales of 188 million pounds in the third quarter of 2024, down from 700 million pounds in the third quarter of 2023.
