FDA Updates Labels for Abrysvo & Arexvy

The Prescribing Information for each vaccine has been revised to include the following language in the Warnings and Precautions section:

• Abrysvo- The results of a postmarketing observational study suggest an increased risk of Guillain-Barré syndrome (GBS) during the 42 days following vaccination with Abrysvo.
• Arexvy- The results of a postmarketing observational study suggest an increased risk of Guillain-Barré syndrome during the 42 days following vaccination with Arexvy.

GBS is a rare disorder in which the body’s immune system damages nerve cells, causing muscle weakness and sometimes paralysis.

New Warning about Risk for GBS Following Vaccination

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, FDA has 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.

About the Study that Assessed the Risk of GBS Following Vaccination

The association between vaccination with Abrysvo and Arexvy and GBS was evaluated among Medicare beneficiaries 65 years of age and older. Using Medicare claims data, between May 2023 through July 2024, vaccinations with Abrysvo and Arexvy were identified through Current Procedural Terminology (CPT)/Healthcare Common Procedure Coding System (HCPCS) codes and National Drug Codes, and potential cases of hospitalized GBS among recipients of Abrysvo and Arexvy were identified through International Classification of Diseases (ICD) codes. GBS diagnoses in claims data were confirmed by medical record review when available.

The risks of GBS following vaccination with Abrysvo and Arexvy were assessed in self-controlled case series analyses using risk windows of 1 to 42 days post vaccination and control windows of 43 to 90 days post vaccination. The analyses of all GBS cases based on claims data suggest an increased risk of GBS during the 42 days following vaccination, with an estimated 9 excess cases of GBS per million doses of Abrysvo, and an estimated 7 excess cases of GBS per million doses of Arexvy administered to individuals 65 years of age and older. Background risks of GBS in study populations influence excess GBS case estimates and may differ between studies and analyses within a study, precluding direct comparisons of excess GBS case estimates from other vaccine studies or populations.

While the results from the self-controlled case series analyses of this observational study suggest increased risks of GBS with Abrysvo and Arexvy, available evidence is insufficient to establish a causal relationship.