Monday, the Centers for Disease Control and Prevention (CDC) reported that reports to the U.S. Vaccine Adverse Events Reporting System (VAERS) indicate a small risk of Guillain-Barré Syndrome (GBS) following receipt of the Johnson & Johnson (J&J) COVID-19 vaccine. About 100 preliminary reports of GBS have been filed with VAERS after the administration of 12.8 million doses of the J&J vaccine. The cases were largely reported about two weeks after vaccination and mostly in males. This pattern has not been seen with the Pfizer and Moderna mRNA vaccines after the administration of more than 321 million doses in the United States. The Food and Drug Administration (FDA) has revised its fact sheets for the J&J vaccine, stating that “Reports of adverse events following use of the Janssen COVID-19 vaccine under emergency use authorization suggest an increased risk of Guillain-Barré syndrome (GBS) during the 42 days following vaccination.” GBS is a rare condition that damages nerve cells. The cause of the condition is unclear. According to CDC, the condition often follows a viral or bacterial infection. It has also been associated with influenza vaccination, although studies suggest one is more likely to get GBS from the flu itself than from a flu vaccine. Most people recover from GBS, but some have had permanent nerve damage. CDC will review data related to the risk of GBS, as well as the overall benefits of the Johnson & Johnson vaccine at an upcoming Advisory Committee on Immunization Practices (ACIP) meeting.