Introduction

: The objective was to assess the im munogenicity and effectiveness of vaccines against SARSCoV-2 in multiple sclerosis (MS) patients included in the Argentinean MS registry.

Methods

: A prospective cohort study between May and December 2021. The primary outcome was im munogenicity and effectiveness of vaccines during a three-month follow-up. Immunogenicity was evalua ted based on detection of total antibodies (Ab) against spike protein and neutralizing Ab in serum 4 weeks after the second vaccine dose. A positive COVID-19 case was defined according to Argentinean Ministry of Health.

Results

: 94 patients were included, mean age: 41.7 ± 12.1 years. Eighty (85.1%) had relapsing remitting mul tiple sclerosis (RRMS); 30 (31.9%) were under fingolimod treatment. The Sputnik V vaccine was the first dose in 33 (35.1%), and AstraZeneca in 61 (64.9%). In 60 (63.8%), the vaccine elicited a specific humoral response. Immu nological response according to the vaccination schemes showed no qualitative differences (p = 0.45). Stratified analysis according to the MS treatment showed that a significantly smaller number of subjects developed anti bodies against spike antigen among those that were on ocrelizumab compared to other groups (p ≤ 0.001), while a reduced number of patients under ocrelizumab where evaluated (n = 7). This was also observed for neutralizing antibodies in the ocrelizumab group (p < 0.001). During the three-month follow-up, two individuals were diag nosed with COVID-19.

Conclusion:

We found that MS patients that recei ved Sputnik V or AstraZeneca vaccines for SARS-CoV-2 developed a serological response with no differences between the vaccines used.