The FDA has mandated that GSK and Pfizer's respiratory syncytial virus (RSV) vaccines include warnings about the potential increased risk of developing Guillain-Barré syndrome (GBS), a rare neurological disorder. This decision follows postmarketing trials that indicated a heightened risk of GBS within 42 days after vaccination. However, the FDA clarified that the available evidence is insufficient to establish a direct causal relationship between the vaccines and GBS.
In the clinical trials for GSK's Arexvy, one participant developed GBS after receiving the vaccine. Similarly, in Pfizer's Abrysvo trial, one participant developed GBS, and another experienced a variant of the condition. Despite these findings, the warnings added to the prescribing information of both vaccines are not the FDA's strictest "boxed" warnings.
Last year, advisors to the CDC had postponed endorsing the use of Arexvy in the 50-59 age group, citing concerns over the risk of GBS. This recent development underscores the importance of monitoring and reporting adverse effects following vaccination to ensure the safety and well-being of the public.
