The following is a summary of recent findings on COVID-related issues in patients with multiple sclerosis.

COVID-19 outcomes: A Veterans Administration database analysis suggested that COVID-related mortality is lower in MS patients on a DMT compared to the general population (Fuchs et al. Mult Scler Relat Disord 2022; epublished June 11, 2022). The study examined records for 49,737 COVID-19 inpatient cases, which included 258 persons with MS. Propensity score matching was also performed. The MS group was not a typical sample: 80% were male, 26% were African-American and 44% were aged >65 years. A total of 19% of MS patients were receiving a DMT (DMF, fingolimod, GA, IFNβ, natalizumab, siponimod or teriflunomide); no patient was on an anti-CD20 therapy. In the PS analysis, the 30-day mortality was non-significantly higher in the MS group (9.4% vs. 8.7%). Mortality risk factors were age >65 (odds ratio 5.93), congestive heart failure (OR 1.96), chronic kidney disease (OR 1.56) and diabetes (OR 1.28). Mortality risk was lower in patients taking a DMT (OR 0.18) and those who had been vaccinated against COVID (OR 0.35).

Booster vaccination (third dose): A UK study examined the response to a booster vaccination in 79 MS patients who had shown no detectable IgG response to the first two COVID vaccinations (Tallantyre et al. Mult Scler Relat Disord 2022; epublished June 4, 2022). Mean age was 45.8 years. Treatments included ocrelizumab (70%), fingolimod (19%) or other immunosuppressants for MS or other medical condition (11%). The mean time from booster to blood draw was 5.9 weeks. One-third demonstrated anti-spike IgG seroconversion following a booster injection and 65% had a positive T cell response. Overall, 78% displayed either a humoral or cellular immune response to the booster.

A German study (N=126) reported differing results (Meyer-Arndt et al. J Neurol Neurosurg Psychiatry 2022; epublished July 14, 2022). In that sample, most MS patients on an anti-CD20 agent or fingolimod showed little to no anti-spike IgG neutralizing activity after a booster injection. Fingolimod-treated patients also had an absence of a spike-reactive CD4+ T cell response. The attenuated B cell response with fingolimod was related to the duration of fingolimod treatment rather than immune cell counts at the time of vaccination. The authors suggested that the impaired immune response was due in part to impeded movement of immune cells to the site of inoculation.

COVID-19 and pregnancy: An analysis of the COViMS Registry propensity-matched 31 women with MS who were pregnant or postpartum at the time of COVID infection with 62 MS controls with COVID (Salter et al. Mult Scler Relat Disord 2022; epublished July 5, 2022). Most COVID infections occurred in 2020 prior to the availability of vaccines. Mean age was 35.6 years; mean duration of MS was 7.0 years. The rate of COVID hospitalization was 3.7% for pregnant women and 11.1% for the postpartum group. Two women (7.4%) on ocrelizumab received monoclonal antibody treatment for CoV-2; neither was hospitalized. There were no deaths. While worse COVID outcomes were not seen in pregnant women with MS, the authors noted that MS patients often receive intense care from multiple physicians, which may have contributed to better outcomes.