Can Specific COVID-19 Vaccine Types Impact Guillain-Barré Syndrome Risk?

There is an association between the development of Guillain-Barré syndrome (GBS) after receiving the first dose of adenovirus-based COVID-19 vaccines. However, there is no statistically significant increased risk for GBS following the administration of mRNA vaccines. These are the findings of a study published in Neurology.

Previous research has identified SARS-CoV-2 infection as a known trigger for GBS. Post-marketing surveillance of the COVID-19 adenovirus-based vaccines has shown several reports of GBS, but research regarding the clinical significance of this adverse effect is unclear. Researchers conducted a study to assess the incidence of GBS after vaccination. 

The researchers linked data from the French National Health Data System to the COVID-19 vaccine database. They screened patients aged 12 and older who were admitted to the hospital for GBS between December 2020 and May 2022. 

The International Classification of Diseases, 10th revision (ICD-10) was used to make a GBS diagnosis. The researchers defined the GBS risk period as 1 to 42 days after receiving a dose of the vaccine and the analysis was broken into 3 14-day intervals. 

Among the 2229 people admitted for GBS, 1838 (82%) received at least 1 COVID-19 vaccine dose. The median age at baseline was 57 and 60% were male patients. The median hospital length of stay was 12 days, with 16% of individuals admitted to the intensive care unit. 

A total of 85 patients with GBS died in the hospital (3%) or within 30 days after discharge (0.9%).

Within 42 days after vaccination, there was increased risk for GBS observed for patients with a:

• positive SARS-CoV-2 test (relative incidence (RI), 3.8; 95% CI, 2.8-5.1),
• hospitalization for COVID-19 (RI, 7.9; 95% CI, 4.3-15),
• respiratory infection (RI, 1.8; 95% CI, 1.4-2.3), or a
• gastrointestinal infection (RI, 4.2; 95% CI, 3.1-5.7).

There was a significantly increased incidence of GBS risk within 15 to 28 days after receiving the first doses of the ChAdOx1-S (RI, 4.8; 95% CI, 3.2-7.3) and the Ad26.COV2.S vaccine (RI, 4.3; 95% CI, 1.8-10). The relative incidence of GBS after the second dose of the ChAdOx1-S vaccine showed no significant differences between time intervals post-vaccine. 

Within 42 days after the first dose of the ChAdOx1-S vaccine, the researchers observed an increased risk for GBS in patients aged 12 to 49 and 50 and older. 

When evaluating all significant associations, researchers estimated the fraction of GBS cases that were attributable to the vaccination at 61% (95% CI, 44-72) for the ChAdOx1-S vaccine and 58% (95% CI, 14-80) for the Ad26.COV2.S vaccine in those aged 12 and older, and 61% (95% CI, 16-82) for the mRNA-1273 vaccine in those aged 12 to 49. 

“In this comprehensive assessment at the French population level, there was no statistically significant increase in risk of Guillain-Barré syndrome after the administration of mRNA vaccines,” researchers wrote. 

Study limitations are a potential underestimation of GBS cases and that cases of gastrointestinal and respiratory infections were defined based on indirect treatment information.