Acute disseminated encephalomyelitis and transverse myelitis following COVID-19 vaccination – A self-controlled case series analysis
Australian study found an increased risk of acute disseminated encephalomyelitis (all dose relative incidence (RI) 3.74; 95% CI 1.02-13.70) and transverse myelitis (dose 1 RI 2.49; 95% CI 1.07-5.79) associated with ChAdOx1, but not with mRNA covid-19 vaccines.
Source:
Vaccine
SPS commentary:
The authors note that these findings “translate to an extremely small absolute risk” of acute disseminated encephalomyelitis (ADEM; 0.78 per million vaccine doses) and of transverse myelitis (1.82 per million vaccine doses), and that any potential risk “should be weighed against the well-established protective benefits of vaccination against covid-19 and its complications.”
These results build upon those of the Global Vaccine Data Network study, that suggested an excess of ADEM and transverse myelitis following ChAdOx1 and mRNA-1273 vaccines compared to historically expected background rates.