Low Incidence of Relapses After Vaccination in Anti‐Aquaporin‐4 Antibody‐Positive <scp>NMOSD</scp>

Patients with neuromyelitis optica spectrum disorder (NMOSD) may experience increased signs and symptoms of their underlying disease when vaccinated against meningococcal disease before receiving complement component 5 inhibitor therapies. This retrospective analysis indicated an overall low relapse incidence (mean [range], 3.3% [0.7%-10.6%]) of physician-reported relapses occurring within 4 weeks of meningococcal vaccination in those screened in CHAMPION-NMOSD (NCT04201262), randomized to eculizumab or placebo in PREVENT (NCT01892345), and from the Japanese postmarketing surveillance of eculizumab in patients with anti-aquaporin-4 antibody-positive NMOSD. Further studies are needed to determine if postvaccination relapses are attributable to vaccination or inherent relapse risk among these patients.