COVID-19 vaccine response in Neuromyelitis Optica Spectrum Disorder

Neuromyelitis Optica Spectrum Disorder (NMOSD) is a disabling autoimmune disease of the central nervous system that requires immunosuppressants to control the relapses. The latter puts them at risk for more severe COVID-19 infection. Vaccines are an effective way to control the pandemic. However, we do not know how effective they are in immunologically compromised patients. We aimed to evaluate and compare antibody levels in NMOSD patients treated with disease-modifying therapies after two doses of inactivated and mRNA COVID-19 vaccines.

Patients with NMOSD diagnosis and age-sex matched healthy controls who received two doses of either inactivated and mRNA COVID-19 vaccine were recruited in the study. Serum samples were collected at least two weeks after the second dose.

Serum samples from 24 NMOSD patients (Mean age-36.58, Female-70.83%) and 24 healthy controls (Mean age-36.71, Female-70.83%) were evaluated. Mean antibody titer was lower in the NMOSD group (Mean; SD (2.43 ± 1.51) than in healthy controls (Mean; SD 3.23 ± 0.80). Seronegativity was only seen in the rituximab group, there were no such cases in the azathioprine group. (9 vs 0).

The study shows that NMOSD patients treated with rituximab may still be susceptible to severe COVID-19 infection even after both inactivated and mRNA vaccines.