Evidence of Extensive Cellular Immune Response after SARS-CoV-2 Vaccination in Ocrelizumab-Treated Patients with Multiple Sclerosis.

Background Patients with multiple sclerosis receiving ocrelizumab-treatment are in desperate need of a protection against SARS-CoV-2 infection. Methods In this study, Euroimmun semi-quantitative Anti-SARS-CoV-2 IgG for detection of humoral response and ELISpot assays for detection of SARS-CoV-2-specific T-cell-response were used in 10 ocrelizumab-treated patients with multiple sclerosis twice vaccinated with Comirnaty® mRNA vaccine. This data was compared with a control group of 20 age- and sex-matched healthy volunteers, who had all previously received a full SARS-CoV-2 mRNA vaccination with Comirnaty® or Spikevax®. Results While all subjects in the control group had high humoral response to the vaccination, in B-cell-depleted individuals a significantly reduced antibody response to vaccination against SARS-CoV-2 was observed. SARS-CoV-2 specific T-cell-response, however, did not differ significantly between both cohorts. Conclusions T-cell-mediated response to Comirnaty® vaccination is observable despite attenuated humoral response in B-cell-depleted patients. This might enable partial protection against COVID-19. Trial registration Retrospectively registered.