Guillain-Barré syndrome risk greater after COVID-19, study indicates

NEW YORK, Oct. 18 (UPI) — A new study indicates that COVID-19 is associated with an elevated risk of a rare disorder, Guillain-Barré syndrome, within six weeks after infection with the virus.

The study was published online Wednesday in Neurology, the medical journal of the American Academy of Neurology.

The research, conducted in Israel, 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 those who developed COVID-19 but did not get the vaccine.

Guillain-Barré syndrome is an autoimmune disorder in which the immune system attacks nerve cells. Symptoms that begin with weakness in the hands and feet may lead to paralysis.

Although Guillain-Barré syndrome can be life-threatening, most people recover with few remaining complications. An exact cause of the condition is unknown, but it can arise after gastrointestinal or respiratory infections.

The syndrome strikes as many as 20 out of every 1 million people per year, and only in extremely rare cases does it occur after certain vaccinations.

Dr. Anat Arbel, the study’s corresponding author, told UPI via email that the researchers noticed a rise in cases of Guillain-Barré syndrome during the pandemic and along with the initiation of a mass COVID-19 vaccination campaign in Israel.

“So far, existing literature regarding the occurrence of GBS after COVID-19 infection and vaccination has been inconclusive,” said Arbel, an internal medicine senior doctor at Lady Davis Carmel Medical Center in Haifa.

“Hence, we aimed to explore the association between GBS [Guillain-Barré syndrome] and both SARS-CoV-2 infection and COVID-19 vaccine in our study.”

Arbel said “the study suggests that SARS-CoV-2 is associated with an increased risk of developing GBS, while Pfizer-BioNTech vaccine is associated with decreased risk of GBS. These findings further highlight the benefits of ongoing vaccination program with mRNA-based vaccines and have important clinical and public health implications.”

The study involved more than 3 million people in Israel with no previous diagnosis of Guillain-Barré. Participants were followed from Jan. 1, 2021, to June 30, 2022. During that period, 76 people developed the syndrome. Each person with Guillain-Barré was matched to 10 people who did not have the syndrome, or 760 people.

Researchers then examined whether participants had a COVID-19 infection or a COVID-19 vaccine during the six weeks before diagnosis of Guillain-Barré or the same time period for their matched participants.

They determined that people with a recent COVID-19 infection were six times more likely to develop Guillain-Barré than those without a recent infection. A total of 12% of the people with Guillain-Barré had a recent COVID-19 infection, compared to 2% of the people who did not have Guillain-Barré.

In addition, 11% of those with Guillain-Barré had been vaccinated recently with a mRNA vaccine, compared to 18% of those who did not have Guillain-Barré.

The researchers also found that people with a recent mRNA vaccination were more than 50% less likely to develop Guillain-Barré than those without a recent mRNA vaccination.

Since not all participants had tests for COVID-19, it is possible that some people may have been classified with no evidence of COVID-19 infection when they had an infection with no symptoms or mild symptoms.

The authors noted that the study does not prove that COVID-19 infection increases the risk of Guillain-Barré or that mRNA vaccination decreases the risk. It only shows an association.

About two-thirds of patients who develop Guillain-Barré syndrome have a symptom of respiratory or gastrointestinal tract infection, Dr. Senda Ajroud-Driss, a neuromuscular disease specialist at Northwestern Memorial Hospital in Chicago, who was not involved in the study, told UPI via email.

As a result, she said she was “not surprised to see that patients who had COVID-19 were at an increased risk of developing GBS.”

However, Ajroud-Driss added that “we have to be careful interpreting the results of a study that shows an association.”

“it is useful to know that patients who receive the mRNA vaccine have less severe symptoms when they develop COVID-19. Therefore, it makes sense that the risk of GBS is also lower, since other studies showed that patients with GBS due to COVID-19 tend to have severe COVID-19 symptoms that require hospitalization,” she said.

Dr. Holli Horak, professor of neurology at the University of Arizona College of Medicine-Tucson, who was not involved in the study, told UPI that the association is important.

“There are other viral illnesses that are associated with an increased risk of GBS. So, having this knowledge helps us when we assess patients and helps us as we counsel patients,” Horak said, adding, “As a physician, I recommend COVID vaccination unless the patient has a compelling reason to avoid vaccination.”

Dr. Eelco Wijdicks, a neuro-intensivist and professor of neurology at Mayo Clinic in Rochester, Minn., who was not involved in the study, said in a telephone interview that the results of the study appear legitimate — that Guillain-Barré syndrome is much more likely due to infection rather than vaccination.

“The study is large, but if audited, likely will have overestimated GBS. Misdiagnosis has been found previously in these types of studies,” Wijdicks said, noting that “GBS can occur as result of any viral infection, and COVID should not be an exception.

“Simply get vaccinated if you want to avoid GBS or any other major neurologic complication.”

As the study’s authors mentioned, “they cannot prove that COVID vaccine and COVID infection can cause or prevent GBS. This will need more investigation and research,” Dr. Arada Wongmek Weerawat, a neuromuscular disease specialist at Northwell Health in New Hyde Park, N.Y., told UPI via email. She was not involved in the study.

Since Guillain-Barré syndrome is a rare disease, Weerawat said, it is difficult to make the correlation.