“…This association warrants further systematic investigation, as COVID-19 vaccination, and in our cases mRNA vaccination, appears to be associated with inflammatory MS disease activity. In real-world safety reports based on MS, MOG antibody disease, neuromyelitis optica spectrum disorder, and transverse myelitis populations (963 patients), exposure to Pfizer-BioNTech COVID-19 vaccine has been associated with new or worsening neurological symptoms in less than ~15% of patients, commonly occurring early in the post-vaccination period (<7 days), and mostly self-resolving within 2 weeks ( Lotan et al, 2021a ; Lotan et al, 2021b ), Although there is evidence of immune activation with vaccines leading to other neuroimmunological disorders such as Guillain-Barré Syndrome, acute disseminated encephalomyelitis, or transverse myelitis, this has not been the case for MS. ( Stone et al, 2019 ; Agmon-Levin et al, 2009 ) Despite broad use of mRNA COVID-19 vaccines, there have been few reports of MS flares in the short-term post-vaccination period as well as optic neuritis and transverse myelitis ( Maniscalco et al, 2021 ; Kaulen et al, 2021 ). A cohort of 555 MS patients receiving at least one dose of Pfizer-BioNTech mRNA COVID-19 vaccine did not experience an increase in relapse rate as compared to the unvaccinated population ( Achiron et al, 2021 ).…”