Saturday, October 21, 2023

Neurology: Association Between Guillain-Barré Syndrome and COVID-19 Infection and Vaccination



Yes, that’s me in 1976, giving Swine Flu Shots.

#17,730

Nearly 50 years ago (1976) the U.S. government rolled out an emergency flu vaccine in anticipation of a swine flu (H1N1) pandemic that never materialized (you can read my first hand account HERE).

Instead, that early flu shot was linked to a modest increase in Guillain-Barré syndrome (GBS) - a rare, often transitory, but occasionally fatal form of paralysis.

Although only about 1 in 100,000 vaccine recipients were thought to be affected - and many of the media accounts were overblown - the safety reputation of vaccines has suffered for decades.  

Even without vaccines, there is always a background rate of GBS - usually 1 to 2 cases per 100,000 each year - often linked to viral or bacterial infections. The CDC describes the disorder:

What is Guillain-Barré syndrome (GBS)?
Guillain-Barré syndrome (GBS) is a rare disorder in which a person’s own immune system damages their nerve cells, causing muscle weakness and sometimes paralysis. GBS can cause symptoms that usually last for a few weeks. Most people recover fully from GBS, but some people have long-term nerve damage. In very rare cases, people have died of GBS, usually from difficulty breathing. In the United States, an estimated 3,000 to 6,000 people develop GBS each year.
What causes GBS?
The exact cause of GBS is unknown, but about two-thirds of people who develop GBS experience symptoms several days or weeks after they have been sick with diarrhea or a respiratory illness. Infection with the bacterium Campylobacter jejuni is one of the most common risk factors for GBS. People also can develop GBS after having the flu or other infections (such as cytomegalovirus and Epstein Barr virus). On very rare occasions, they may develop GBS in the days or weeks after getting a vaccination. 
Clusters of GBS are relatively rare, but we have looked at a few (see 2011's The Sonora/Arizona GBS Cluster). In this particular case, the outbreak was linked to inadequately disinfected tap water (see Binational outbreak of Guillain-Barré syndrome associated with Campylobacter jejuni infection, Mexico and USA, 2011.

Following the 2015/2016 outbreak and spread of the Zika virus in the Americas, Zika virus infection has been linked to the development of GBS . We've also seen repeated outbreaks reported over the past 5 years in Peru. 

Despite research indicating you are far more likely to develop GBS in the weeks following an influenza infection than you are after getting the flu vaccine (see Lancet: The Influenza - Guillain Barré Syndrome Connection), the GBS stigma remains. 

Similar concerns have been raised over COVID shots, often amplified by anti-vaccine activists.  

This week we've a study, published in the Journal Neurology, that finds your risks of developing GBS increase 6-fold following COVID infection, while receipt of the COVID vaccine is linked to a significantly decreased risk. 


October 18, 2023 RESEARCH ARTICLE
Association Between Guillain-Barré Syndrome and COVID-19 Infection and Vaccination: A Population-Based Nested Case-Control Study
Haya Bishara, Anat Arbel, Ofra Barnett-Griness, Sivan Bloch, Shai Cohen, Ronza Najjar-Debbiny, Naomi Gronich, Eitan Auriel, Walid Saliba
First published October 18, 2023, DOI: https://doi.org/10.1212/WNL.0000000000207900

While the full study is behind a paywall, we've the following press release summarizing its findings.   I'll have a postscript after the break.
STUDY FINDS INCREASED RISK OF GUILLAIN-BARRÉ AFTER COVID-19 INFECTION
DECREASED RISK FOUND AFTER MRNA VACCINE


MINNEAPOLIS – Having a COVID-19 infection is associated with an increased risk of developing the rare disorder called Guillain-Barré syndrome within the next six weeks, according to a study published in the October 18, 2023, online issue of Neurology®, the medical journal of the American Academy of Neurology. 

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-Barré 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-Barré 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. 

“These findings further highlight the benefits of ongoing vaccination programs with mRNA-based vaccines,” said study author Anat Arbel, MD, of Lady Davis Carmel Medical Center in Haifa, Israel.

“The results have important clinical and public health implications.” The study involved over 3 million people in Israel with no previous diagnosis of Guillain-Barré. They were followed from January 1, 2021, until June 30, 2022. During that time, 76 people developed Guillain-Barré. Each person with Guillain-Barré 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-Barré 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-Barré than those without a recent infection. A total of 12% of the people with Guillain-Barré had a recent COVID infection, compared to 2% of the people who did not have Guillain-Barré. In addition, 11% of those with Guillain-Barré had a recent vaccination with a mRNA vaccine, compared to 18% of those who did not have Guillain-Barré. 

They 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. 

“While Guillain-Barré 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,” 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-Barré or that mRNA vaccination decreases the risk. It only shows an association. 

Learn more about COVID-19 and Guillain-Barré at BrainandLife.org, home of the American Academy of Neurology’s free patient and caregiver magazine focused on the intersection of neurologic disease and brain health. Follow Brain & Life® on Facebook, Twitter and Instagram.

          (Continue . . . )

The decision to take any vaccine or medication always involves a risk-reward calculation. Most of the time, the small risk from a vaccine is more than justified, given the protection it provides. 

While there may be some minuscule risk of developing GBS following receipt of a vaccine, it pales in comparison to other exposures.

In addition to Zika and COVID, many other viral infections - including Dengue, Chikungunya, and West Nile Virus - have been linked to GBS (see Atypical Neurological Manifestations of Chikungunya Fever: Two Case Reports).  
 
As these viral illnesses spread into new regions, increases in GBS are likely. Outbreaks, or unusual clustering of GBS, are normally linked to some environmental toxin, or infectious agent.  GBS itself is not contagious.

The NIH maintains an extensive website on GBS:

Posted by at