FDA Requires Abrysvo, Arexvy RSV Vaccine Labels to Include Guillain-Barré Warning
Patients who receive either Pfizer or GSK’s respiratory syncytial virus vaccine may be at increased risk of Guillain-Barré syndrome.
The FDA is now requiring respiratory syncytial virus (RSV) vaccine manufacturers Pfizer and GSK to update their product prescribing information to include the vaccine’s increased risk of subsequent Guillain-Barré syndrome (GBS), according to an FDA news release.1
“[GBS] is a rare neurological disorder in which a person’s immune system mistakenly attacks part of their peripheral nervous system—the network of nerves that carries signals from the brain and spinal cord to the rest of the body,” according to the National Institute of Neurological Disorders and Stroke (NINDS).2 “GBS begins suddenly and can increase in intensity over a period of hours, days, or weeks until certain muscles cannot be used at all.”
GBS is a neurological disorder that impacts a person’s immune system and mistakenly attacks part of their peripheral nervous system. | image credit: Dzmitry / stock.adobe.com
The 2 brand-name RSV vaccines currently approved and available to eligible patients are Pfizer’s Abrysvo and GSK’s Arexvy—which is an adjuvanted version of the RSV vaccine. Arexvy was the first product to receive FDA approval on May 3, 2023, and shortly after, Abrysvo was given approval on May 31, 2023. Both vaccines were manufactured to prevent lower respiratory tract disease (LRTD) caused by RSV in individuals 60 years of age and older.
READ MORE: Important Updates in RSV Vaccination Guidelines | ASHP Midyear
While the FDA has not presented data that triggered a warning label for these vaccines, the main property GBS and RSV have in common is how each disease can impact respiratory health. According to the NINDS, GBS typically occurs after a respiratory or gastrointestinal bacterial or viral infection.2 With RSV serving an even greater risk to the respiratory system, individuals eligible to receive Abrysvo or Arexvy may already be at risk of GBS, even prior to receiving a vaccination.
Furthermore, despite occurring in “very rare cases,” vaccinations have been reported as possibly increasing GBS risk; these rare cases were reported before the FDA’s warning label.
Now, with minimal but further understanding of the RSV vaccine’s impact on GBS risk, the FDA is enforcing similar requirements for both vaccine manufacturers. The new warning label will read: “The results of a postmarketing observational study suggest an increased risk of Guillain-Barré syndrome during the 42 days following vaccination.”1
While more data is needed for experts to fully understand the links between RSV vaccination and GBS, issuing a warning label was ultimately the FDA’s first step in order to ensure minimal patient impact. However, this may pose an unforeseen challenge for both Pfizer and GSK, who have been striving for further indications amongst their vaccines since initial approvals back in 2023.
“Pfizer’s RSV vaccine Abrysvo has been approved by the FDA for the prevention of RSV-associated LRTD in individuals aged 18 to 59 who are at increased risk of disease. This unadjuvanted, bivalent RSV prefusion F (RSVpreF) vaccine is the first and only RSV vaccine indicated for adults younger than 50 years,” wrote Lauren Biscaldi, MS, for Drug Topics.3
While Pfizer continues to find new indications for its vaccine, GSK has also recently reported on its vaccine’s continued success. According to data presented at CHEST 2024, Arexvy has maintained significantly effective protection against LRTD through 3 RSV seasons.
“We are excited by these new data which show that a single dose of Arexvy could help protect millions of older adults at risk of RSV over 3 seasons and benefit public health,” said Tony Wood, GSK’s chief scientific officer.4 “This is the only RSV vaccine with efficacy and safety data available through 3 full seasons.”
As more research is conducted regarding immunization’s link to GBS, the FDA encourages any patients with adverse reactions to RSV vaccines to report them to the Vaccine Adverse Event Reporting System (VAERS) in the meantime.
While the warning label for both manufacturers’ RSV vaccine does not undo the work each has done to save millions of lives, it’s a crucial piece of information that can ultimately improve public health—as long as pharmacists, physicians, and other certified vaccinators relay the proper education to their patients.
READ MORE: Immunization Resource Center
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