FDA adds Guillain-Barré syndrome warning to GlaxoSmithKline’s shingles vaccine
The FDA late Wednesday sent out a safety communication to explain that while GlaxoSmithKline’s shingles vaccine Shingrix is a safe vaccine, it’s now added a new warning to the label noting an increased risk of a rare but debilitating disorder known as Guillain-Barré syndrome (GBS).
“In a postmarketing observational study, an increased risk of GBS was observed during the 42 days following vaccination with Shingrix,” the updated Warnings and Precautions section of the label now says. The FDA also determined that the benefits of vaccination with Shingrix continue to outweigh its risks.
The FDA said in its safety communication that it found the risk by combing through Medicare claims data from more than 3.7 million vaccinations with Shingrix between October 2017 and February 2020.
“The primary analysis (claims-based, all doses) found an increased risk of GBS during the 42 days following vaccination with Shingrix, with an estimated 3 excess cases of GBS per million doses administered to adults aged 65 years or older,” FDA said. “In secondary analyses, an increased risk of GBS was observed during the 42 days following the first dose of Shingrix, with an estimated 6 excess cases of GBS per million doses administered to adults aged 65 years or older, and no increased risk of GBS was observed following the second dose of Shingrix.”
Each year in the US, an estimated 3,000 to 6,000 people develop GBS, FDA said, which is about 10 to 20 cases of GBS per million people each year.
The FDA also acknowledged that it did not identify an increased risk for GBS in its evaluation of the clinical trials data for Shingrix, which the agency evaluated prior to the vaccine’s approval in 2017.
“Rare adverse events, some of which may be serious, may become apparent with more widespread use of the vaccine,” the agency said.
GSK told Endpoints News in a statement, “GSK remains confident in the favorable benefit-risk profile of SHINGRIX for the prevention of shingles. We will continue to communicate with FDA and CDC on post-marketing safety monitoring for SHINGRIX.”
The statement also noted that at the February 2021 meeting of the CDC Advisory Committee on Immunization Practices, the Herpes Zoster Work Group presented results of a comprehensive risk-benefit analysis of Shingrix that included a review of post-marketing data. “The analysis concluded: GBS is rare, and data on the risk of GBS following HZ (herpes zoster or ‘shingles’) and vaccination are limited. Clinical trials, observational studies and the risk-benefit analysis confirm the considerable benefits of RZV (SHINGRIX) vaccination in preventing HZ, severe disease and complications.”