Seroconversion after COVID-19 vaccination for multiple sclerosis patients on high efficacy disease modifying medications

The impaired ability to mount an effective immune response to vaccination leaves immunosuppressed patients at higher risk of severe COVID-19 infection. This retrospective study aimed to evaluate COVID-19 seroconversion and antibody titers for patients on immune modulating therapies compared to those not on disease modifying therapy (DMT). As expected, individuals on B-cell depletion therapies (BCDT) and those on sphingosine 1-phosphate (S1P) modulators had an impaired humoral response to mRNA vaccination. We observed variable seroconversion depending on the type of B-cell depleting medication, with a smaller percentage of seroconversion in patients on infused BCDT (iBCDT, ocrelizumab and rituximab) compared to ofatumumab. The humoral response to vaccination was not impaired for individuals on natalizumab or for untreated MS patients. These observations may influence DMT selection during the COVID-19 era.