ABSTRACT
Introduction: Patients with multiple sclerosis (MS) often receive disease-modifying therapies (DMTs) which can reduce the response to vaccines. BNT162b2 (Pfizer-BioNTech) is the first COVID-19 vaccine authorized in Italy but was not evaluated in MS patients receiving DMTs. Objectives: To evaluate serological response and safety to BNT162b2 in patients with MS. Methods: This is an early multicenter, case-control and prospective study. Patients were healthcare workers (HCWs) with MS, receiving at least one DMT, and having received BNT162b2. Blood samples were collected between 2 and 6 weeks after the second vaccine dose and analyzed to quantify anti-Spike antibodies (Abbott). Anti-Spike cut-off for response was set at 7.1 BAU/ ml. Anti-Spike levels in patients considered at-risk of reduced response were compared to those considered non-at-risk, according to literature and expert consensus. Anti-Spike levels were compared to those of a control population of HCWs, without MS or immune-related disease, untreated, and having received BNT162b2. Total follow up was of 9 weeks from the first vaccine dose. Results: From February 2020, 39 MS patients were enrolled. One patient, treated with ocrelizumab, did not develop serological response (1.8 BAU/ml). The remaining patients responded to the vaccine, including two ocrelizumab-treated patients. The control population consisted of 273 HCWs. All controls responded to BNT162b2. Median anti-Spike levels in patients (1471.0 BAU/ ml;range 779.7-2357.0) and controls (1479.0 BAU/ml;range 813.1-2528.0) were comparable. Patients receiving at-risk treatments (n=9;5 fingolimod, 3 ocrelizumab, 1 natalizumab) showed significantly reduced median anti-Spike levels (241.9 BAU/ml;range 40.2-530.0) compared to non-at-risk (n=30;15 dimethyl fumarate, 5 teriflunomide, 4 interferons, 3 glatiramer acetate, 2 cladribine, 1 alemtuzumab) ones (1707.7 BAU/ml;range 1356.2- 2432.8) (p<0.001). No COVID-19 cases were reported. Two patients had a clinical MS relapse after 17 and 30 days after the second dose. A causal relationship with the vaccination could not be established. Conclusions: In our study, most MS patients produce a serological response to BNT162b2 similar to non-MS controls;however, at-risk DMTs resulted in reduced anti-Spike levels and one ocrelizumab- treated patient did not respond. These observations should be better investigated and replicated in larger studies to support clinical decision in COVID-19 vaccine management.