EMBARGOED FOR RELEASE UNTIL 4 PM ET, October 18, 2023
Study Finds Increased Risk of Guillain-Barré After COVID-19 Infection
Decreased Risk Found After mRNA Vaccine
MINNEAPOLIS 鈥 Having a COVID-19 infection is associated with an increased risk of developing the rare disorder called Guillain-Barr茅 syndrome within the next six weeks, according to a study published in the October 18, 2023, online issue of , the medical journal of the 好色先生. The study also found that people who received the mRNA vaccine from Pfizer-BioNTech were less likely to develop the disorder in the next six weeks than people who did not receive the mRNA vaccine. Guillain-Barr茅 syndrome is a rare autoimmune disorder in which the immune system attacks nerve cells. Symptoms start with weakness in the hands and feet and may progress to paralysis. Although it can be life-threatening, most people recover with few remaining problems. An exact cause of Guillain-Barr茅 syndrome is unknown but it can occur after gastrointestinal or respiratory infections. Researchers note it occurs in up to 20 out of every one million people per year, and only in extremely rare cases does it follow certain vaccinations. 鈥淭hese findings further highlight the benefits of ongoing vaccination programs with mRNA-based vaccines,鈥 said study author Anat Arbel, MD, of Lady Davis Carmel Medical Center in Haifa, Israel. 鈥淭he results have important clinical and public health implications.鈥 The study involved over 3 million people in Israel with no previous diagnosis of Guillain-Barr茅. They were followed from January 1, 2021, until June 30, 2022. During that time, 76 people developed Guillain-Barr茅. Each person with Guillain-Barr茅 was matched to 10 people who did not have the syndrome, or 760 people. Then researchers looked to see whether participants had a COVID infection or a COVID vaccine during the six weeks prior to the diagnosis of Guillain-Barr茅 or the same time period for their matched participants. Researchers determined that people with a recent COVID infection were six times more likely to develop Guillain-Barr茅 than those without a recent infection. A total of 12% of the people with Guillain-Barr茅 had a recent COVID infection, compared to 2% of the people who did not have Guillain-Barr茅. In addition, 11% of those with Guillain-Barr茅 had a recent vaccination with a mRNA vaccine, compared to 18% of those who did not have Guillain-Barr茅. They also found that people with a recent mRNA vaccination were more than 50% less likely to develop Guillain-Barr茅 than those without a recent mRNA vaccination. 鈥淲hile Guillain-Barr茅 is extremely rare, people should be aware that having a COVID infection can increase their risk of developing the disorder and receiving an mRNA vaccine can decrease their risk,鈥 Arbel said. A limitation of the study was that since not all participants had tests for COVID, it is possible that some people may have been classified with no evidence of COVID infection when they had an infection with no or mild symptoms. The study does not prove that COVID infection increases the risk of Guillain-Barr茅 or that mRNA vaccination decreases the risk. It only shows an association. Learn more about COVID-19 and Guillain-Barr茅 at , home of the 好色先生鈥檚 free patient and caregiver magazine focused on the intersection of neurologic disease and brain health. Follow Brain & Life庐 on , and . When posting to social media channels about this research, we encourage you to use the hashtags #Neurology and #AANscience.