The U.S. Food and Drug Administration (FDA) has issued a safety communication requiring that a warning about the risk of Guillain-Barré Syndrome (GBS) be added to the prescribing information for two respiratory syncytial virus (RSV) vaccines, Abrysvo (Pfizer) and Arexvy (GSK). This action follows post-marketing surveillance that suggested a possible association between these vaccines and an elevated risk of GBS, a rare autoimmune disorder in which the immune system attacks the peripheral nerves.
GBS can lead to muscle weakness and, in severe cases, paralysis. While GBS is rare, with an estimated incidence of 1 to 2 cases per 100,000 people annually, the FDA's decision reflects a cautious approach to vaccine safety. The FDA emphasizes that the benefits of Abrysvo and Arexvy in preventing severe RSV disease continue to outweigh the potential risks.
Clinical Considerations
Healthcare providers are now advised to be aware of the potential for GBS in individuals who have recently received Abrysvo or Arexvy. Symptoms of GBS can include weakness or tingling sensations in the legs or arms, which can spread to the upper body. In some instances, these symptoms can rapidly progress to paralysis, requiring hospitalization and intensive care.
The FDA's safety communication does not provide specific details on the number of GBS cases observed following vaccination or the strength of the association. However, the agency's decision to add the warning suggests a level of concern that warrants increased vigilance among healthcare professionals.
Context of RSV Vaccination
Abrysvo and Arexvy were approved in 2023 for the prevention of RSV in older adults. RSV is a common respiratory virus that can cause severe illness in infants, young children, and older adults. Vaccination is a key strategy for reducing the burden of RSV-related disease in these vulnerable populations.
The addition of a GBS warning to the prescribing information for Abrysvo and Arexvy highlights the importance of ongoing safety monitoring for newly approved vaccines. While pre-approval clinical trials are designed to identify common adverse events, rare side effects may only become apparent after a vaccine is widely used in the general population. The FDA's action underscores its commitment to promptly addressing potential safety concerns and ensuring that healthcare providers and patients have the information they need to make informed decisions about vaccination.
