FDA Requires Guillain-Barré Warning for Abrysvo and Arexvy

The FDA is requiring safety labeling changes to the prescribing information for the respiratory syncytial virus vaccines Abrysvo and Arexvy to add a new warning about the risk for Guillain-Barré syndrome (GBS).

The labels for both Abrysvo, manufactured by Pfizer, and Arexvy, manufactured by GSK, have been updated to include to say “postmarketing observational study suggest an increased risk of Guillain-Barré syndrome during the 42 days following vaccination.”

Guillain-Barré syndrome is a neurological disorder in which a person’s immune system attacks part of their peripheral nervous system, causing muscle weakness and sometimes paralysis.

Both vaccines were approved in May 2023 to prevent lower respiratory tract disease (LRTD) caused by RSV in people 50 years of age and older. Abrysvo is approved to be given to pregnant women to prevent RSV in infants.

The FDA conducted a postmarketing observational study that assessed the risk of GBS following vaccination with Abrysvo and Arexvy. Based on FDA’s evaluation of data from clinical trials, reports to the Vaccine Adverse Event Reporting System (VAERS), and the postmarketing study, regulators have determined that the overall body of evidence suggests increased risks of GBS with Abrysvo and Arexvy, but that available evidence is insufficient to establish a causal relationship.

The association between vaccination with Abrysvo and Arexvy and GBS was evaluated among Medicare beneficiaries 65 years of age and older between May 2023 through July 2024. The FDA found that there was an estimated nine excess cases of GBS per million doses of Abrysvo and an estimated seven excess cases of GBS per million doses of Arexvy

Regulators say, however, the benefits of vaccination with Abrysvo and Arexvy continue to outweigh their risks.

“Continuous monitoring and assessment of the safety of all vaccines remain an FDA priority and we are committed to informing the public when we learn new information about these vaccines,” regulators said in a safety communication.