Assessment of the breadth of spike antibody mediated protection after COVID-19 vaccinations in patients with MS

ABSTRACT

Background: Current SARS-CoV-2 vaccines rely on protective immunity against early clade SARS-CoV-2 and have resulted in seroconversion in a subset of MS patients receiving immunosuppressive DMTs. However, it is unknown if SARS-CoV-2 spike antibodies afford immunity against emerging variants of concern, such as Delta and Omicron. Objective(s) To determine the binding of spike antibodies to early clade, Delta, and Omicron SARS-CoV-2 in patients with MS receiving different DMTs. Method(s) Spike antibody binding to early clade SARS-CoV-2, Delta and Omicron was assessed by flow cytometry using sera collected from 58 patients one month post second dose and one patient 1 month post third dose. All patients were previously determined to be seropositive against Wuhan (early clade spike). Clinical and demographic information including DMT treatment and vaccination timing was collected. Result(s) 53 patients were seropositive for Wuhan, Delta and Omicron spike antibodies. Wuhan Spike antibody titres were high at one month post second vaccination, whereas Delta and Omicron Spike antibody titres were significantly decreased. We observed a 70% and 93% decrease of in immunoreactivity to Delta and Omicron, respectively. Although ocrelizumab and fingolimod decrease Spike antibody titres after vaccination, they did not affect immunoreactivity to variants, in comparison to other DMTS. Conclusion(s) All 53 patients were able to generate a positive antibody response following vaccination. However, there was an observable decrease in the antibody titres and immunoreactivity to the Delta and Omicron variants, in comparison to Wuhan.