MONDAY, March 21, 2022 (HealthDay News) -- No safety signal is observed between COVID-19 vaccines and immune-mediated neurological events, but infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is associated with increased risks for Bell palsy, encephalomyelitis, and Guillain-Barré syndrome, according to a study published online March 16 in The BMJ.
Xintong Li, from the University of Oxford in the United Kingdom, and colleagues examined the association between COVID-19 vaccines, SARS-CoV-2 infection, and the risk for immune-mediated neurological events in a population-based historical rate comparison study. Data were included from 8,330,497 people in the United Kingdom and Spain who received at least one dose of COVID-19 vaccines: ChAdOx1 nCoV-19, BNT162b2, mRNA-1273, or Ad.26.COV2.S. The study sample also included 735,870 unvaccinated individuals with a positive reverse transcription polymerase chain reaction test result for SARS-CoV-2 and 14,330,080 individuals from the general population.
The researchers found that for Bell palsy, encephalomyelitis, and Guillain-Barré syndrome, postvaccination rates were consistent with expected rates. In a self-controlled case series conducted for Bell palsy, there were no safety signals seen for vaccinated individuals. However, the rates were higher than expected after SARS-CoV-2 infection. Using data from the United Kingdom, the standardized incidence ratios were 1.33, 6.89, and 3.53 for Bell palsy, encephalomyelitis, and Guillain-Barré syndrome, respectively. Transverse myelitis was rare and could not be analyzed.
"In line with our findings, several other studies have also reported increased risks of immune-mediated neurological events after SARS-CoV-2 infection," the authors write.
One author disclosed financial ties to the pharmaceutical industry.