Disanto G, Sacco R, Bernasconi E, et al. - Studies have shown that patients with multiple sclerosis (MS) can be safely administered the messenger RNA (mRNA) vaccine against SARS-CoV-2, however, there was markedly reduced humoral response to the vaccine when patients were receiving treatment with fingolimod and ocrelizumab. Researchers herein conducted a prospective observational cohort study with the aim to replicate these findings, investigate other disease-modifying treatments (DMTs), and determine whether IgG production following vaccination can be potentiated by delaying anti-CD20 infusions.

• Recruited were 120 patients fulfilling the following criteria: a diagnosis of MS (using the 2017 McDonald criteria); age older than 18 years; and being scheduled for SARS-CoV-2 mRNA vaccine (mRNA-1273 [Moderna] or BNT162b2 [Pfizer]).

• Among participants, following treatment groups were there: anti-CD20 (n = 58: ocrelizumab = 32, rituximab = 25, ofatumumab = 1), sphingosine-1-phosphate receptor (S1P) modulators (n = 9: fingolimod = 7, ozanimod = 2), cladribine (n = 15), teriflunomide (n = 24), and no therapy (n = 14).

• Researchers performed analysis of serum samples obtained at t0 (within 2 weeks prior to first vaccine dose) and t1 (21-35 days after the second dose).

• Findings revealed appropriate humoral response against SARS-CoV-2 at 1 month after vaccination under treatment with cladribine and teriflunomide and diminished/absent response under treatment with anti-CD20 therapies and S1P modulators.

• The probability of developing appropriate humoral responses increases with delaying anti-CD20 infusions by 3 to 6 months before vaccination, especially in selected clinically and radiologically stable patients.