MS patients on certain DMTs may have limited protection from COVID-19 vax

The overall rate of hospitalization for COVID-19 is low among patients with multiple sclerosis (MS) treated with disease-modifying therapies (DMTs) who have been vaccinated against COVID-19, according to a prospective study from England. However, patients on ocrelizumab or fingolimod have elevated hospitalization rates.

The researchers used data from the National Health Service (NHS) England and NHS Improvement and the UK Health Security Agency to identify all patients with MS on DMTs who had received COVID-19 vaccinations between December 2020 and 2021 in England. Of these, 29,353 patients had received two doses of the vaccine. The DMTs used in this patient population were alemtuzumab, beta-interferons, cladribine, dimethyl fumarate, fingolimod, glatiramer acetate, natalizumab, ocrelizumab, and teriflunomide.

Among patients on DMTs who had been vaccinated, the rates of hospitalization for COVID-19 were highest among patients on ocrelizumab (140 per 10,000 persons) and fingolimod (94 per 10,000 persons). [AAN 2022, abstract 0-630]

This was in contrast to much lower rates among patients on alemtuzumab or dimethyl fumarate (37 and 32 per 10,000 persons, respectively) or those on beta-interferons or teriflunomide (0 per 10,000 persons each).

The rates of in-hospital mortality from COVID-19 were generally low but higher among patients on ocrelizumab or natalizumab (2 and 1.2 per 1,000 persons, respectively) compared with those on beta-interferons (0.7 per 1,000 persons), cladribine, dimethyl fumarate, fingolimod (0.3 per 1,000 persons each), or alemtuzumab, glatiramer acetate, or teriflunomide (0 per 1,000 persons each).

When the population was limited to those with a positive COVID-19 test result, hospitalizations for COVID-19 remained highest among vaccinated patients on ocrelizumab, fingolimod, and alemtuzumab (112, 77, and 62 per 1,000 persons, respectively). In-hospital COVID-19–related mortality was highest among patients on cladribine, ocrelizumab, and natalizumab (1.8, 1.6, and 1.5 per 100 persons, respectively).

Among patients who received a third dose of the COVID-19 vaccine (booster dose), the hospitalization rate was 6 and 14 percent among patients on ocrelizumab and fingolimod, respectively, though none ended in death. There were no hospitalizations among patients who were taking any of the other DMTs.

A previous study conducted between April and December 2020 found a 19.7-percent hospitalization rate and 3.3-percent mortality rate in a North American population of patients with MS who tested positive for COVID-19. [JAMA Neurol 2021;78:699-708]

“[In the present study,] although COVID-19–related hospitalization rate for vaccinated MS patients on DMTs was lower than [during] early stages of the pandemic, it was still higher for ocrelizumab or fingolimod [recipients],” said study author Dr Afagh Garjani from the University of Nottingham, Nottingham, UK, and co-authors, at AAN 2022.

In addition, COVID-19–related mortality among vaccinated MS patients on DMTs was lower than during the early pandemic period but remained higher in ocrelizumab recipients, they said.

Despite these findings, the authors highlighted that further research is warranted to establish if the higher hospitalization and mortality rates are due to ineffectiveness of the COVID-19 vaccines in certain patient populations, treatment regimens, or SARS-CoV-2 variants.

The duration of protection provided by the COVID-19 vaccine, effect of COVID-19 treatment measures, and the role of age, frailty, and socioeconomic status on the outcomes in MS patients on DMTs also need to be identified, they said.