A disproportionality analysis for the association of central nervous system demyelinating diseases with COVID-19 vaccination using the World Health Organization pharmacovigilance database

Background: Limited information is available on associations between COVID-19 vaccines and central nervous system (CNS) demyelinating diseases. Objectives: We investigated potential safety signals for CNS demyelinating diseases related to COVID-19 vaccines using the World Health Organization pharmacovigilance database. Methods: Disproportionality analyses of CNS demyelinating disease following COVID-19 vaccination were performed by calculating the information component (IC) or the reporting odds ratio (ROR) compared with those for the entire database and for all other viral vaccines. Results: We identified 715 cases of optic neuritis, 515 of myelitis, 220 of acute disseminated encephalomyelitis (ADEM), and 2840 total CNS demyelinating events adverse drug reactions from July 2020 through February 2022. For mRNA-based and ChAdOx1 nCoV-19 vaccines, there were no potential safety signals of disproportionality for optic neuritis (IC₀₂₅ = −0.93, ROR₀₂₅ = 0.38; IC₀₂₅ = −1.76, ROR₀₂₅ = 0.26), myelitis (IC₀₂₅ = −0.69, ROR₀₂₅ = 0.50; IC₀₂₅ = −0.63, ROR₀₂₅ = 0.53), ADEM (IC₀₂₅ = −1.05, ROR₀₂₅ = 0.33; IC₀₂₅ = −1.76, ROR₀₂₅ = 0.20), or overall CNS demyelinating disease events (IC₀₂₅ = −0.66, ROR₀₂₅ = 0.52; IC₀₂₅ = −1.31, ROR₀₂₅ = 0.34) compared with other viral vaccines. Conclusion: As with other viral vaccines, our disproportionality analyses indicate that the risk of COVID-19 vaccine-associated CNS demyelinating disease was low.