COVID-19 vaccination did not increase risks for rare neurological conditions among more than 8 million people who had received at least one dose of a vaccine from AstraZeneca AZN.L, Pfizer PFE.N/BioNTech 22UAy.DE, Moderna MRNA.O or Johnson & Johnson JNJ.N.
This is in accordance with researchers whose study also included 735,870 unvaccinated individuals who had tested positive for the coronavirus.
As well as older data on an additional 14.3 million people from the general population for a baseline estimate of rates of the neurological conditions before the pandemic.
Researchers looked for four neurological disorders involving the immune system.
Three of them – Bell’s palsy (facial weakness), encephalomyelitis (inflammation of the brain and spinal cord), and Guillain-Barré syndrome (a nerve condition) – were no more common in the vaccine recipients than in the general population, the researchers reported this week in The BMJ.
The fourth – transverse myelitis (inflammation of the spinal cord) – occurred too rarely for analysis (fewer than 5 cases in 8.3 million vaccinated people).
The researchers did see increased rates of Bell’s palsy, encephalomyelitis and Guillain-Barré syndrome in COVID-19 survivors, however.
More research is needed to look for longer term adverse events of vaccination and SARS-CoV-2 infection and to study the effects of vaccines on different age groups, the researchers said.
But it appears that COVID-19 vaccines are “a highly unlikely reason” for most neurological problems, they concluded.