Pfizer COVID-19 Vaccine Safe for Patients With Multiple Sclerosis

Anat Achiron, MD, PhD, FAAN

Data recently presented at the 37th Congress of the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS), October 13-15, suggest that the Pfizer/BioNTech COVID-19 mRNA vaccine, BNT162b2, is safe for use in patients with multiple sclerosis (MS). 

Anat Achiron, MD, PhD, FAAN, professor of neurology, Sackler School of Medicine, Tel-Aviv University; and director and chair, Multiple Sclerosis Center, Sheba Medical Center, Tel-Hashomer, Israel, presented findings from previously published studies, outlining immunity generated following vaccination for patients with MS. According to Achiron, a total of 555 patients with MS in Israel received the first dose of the Pfizer COVID-19 vaccine between December 20, 2020, and January 25, 2021, with 435 patients later receiving the second dose^.1 

During the median follow up period of 20 days after the first vaccine dose and 38 days after the second dose, investigators found no increased risk of relapse activity for patients with MS and patients with acute relapse rate were comparable to nonvaccinated patients during the follow-up period.

Investigators evaluated differences in humoral SARS-CoV2 immunoglobulin G (IgG) response post-vaccination using anti-spike protein-based serology in patients treated with different high-efficacy DMTs. Investigators found that patients taking fingolimod (Gilenya; Novartis) and ocrelizumab (Ocrevus; Genentech) had a significant decrease in protective humoral immune response after vaccination. Also noted was a decrease in SARS-CoV2–specific B-cell and T-cell cellular responses. Comparably, patients who were not treated with a DMT and those treated with cladribine (Mavenclad; EMD Serono) had similar responses in protective humoral and cellular immune responses to healthy subjects after vaccination. 

“Our findings demonstrated that, in patients that are not treated, similar to cladribine-treated MS patients and to healthy subjects, there was a very high percentage—almost 100%—of positive-IgG response at a high level,” Achiron said during her presentation.¹ “However, looking at fingolimod treated-MS patients, only 1 patient had a very low level of antibodies, and only 22.7% of ocrelizumab-treated patients developed protective immune response. These findings are not surprising, as already it has been reported for ocrelizumab- and fingolimod-treated patients, that they have reduced response to tetanus toxoid and influenza vaccines.”

READ MORE: Race, Ethnicity May Affect DMT Response and Tolerability in Multiple Sclerosis

Also noted was a similar profile of adverse events (AEs) for these patients, compared to the general vaccinated population. Most commonly reported AEs in both groups were pain at injection site, fatigue, and headache. Younger patients with MS, patients with lower disability, and patients treated with DMTs did have a slight increase in AEs, Achrion noted.

“Looking at the immune response, we know that there are 2 major pillars—the humoral immune pillar, whereby B-cells are producing antibodies at the first encounter with the antigen or the virus, and thereafter, we need cellular adaptive immune response by memory B-cells and T-cells,” Achiron said, discussing preliminary data from another recent study and the potential need for a COVID-19 vaccine booster in this patient population.1 “We decided to evaluate the immune response in relation also to the cellular immune response.”

Reviewing the unpublished data, Achiron noted that SARS-CoV-2-specific B-cells and T-cells were only found in healthy subjects, untreated patients with MS, and patients with MS treated with cladribine. T-cell response was present for patients treated with ocrelizumab, but B-cell response was impaired, and those treated with fingolimod failed to develop B-cell and T-cell responses. 

Following observations in immune response, investigators provided suggestions for vaccination for patients with MS treated with different DMTs. Cladribine-treated patients should wait at least 4.4 months after their last dosing to receive the COVID-19 vaccine, ocrelizumab-treated patients should wait at least 8.9 months after the last dosing—especially if the patient is over the age of 60—and fingolimod-treated patients should consider switching to a DMT that has been deemed vaccine-safe. Those who are not being treated with a DMT have no vaccine restrictions, according to investigators. The recommended absolute lymphocyte count is greater than 1000 cell/m3, with patients followed for SARS-COV-IgG response between 3 to 6 months after vaccination.

Since the previous report, investigators led by Sapir Dreyer-Alster, BSc, Multiple Sclerosis Center, Sheba Medical Center, Tel-Hashomer, Israel, evaluated expanded data from 888 patients with MS who received their second vaccine dose between December 2020 and April 201. Findings further confirmed that the BNT162b2 vaccine is safe for this patient population, with no increased risk of acute relapse activity.²

Also presented at ECTRIMS 2021were data on the safety and efficacy of the Pfizer COVID-19 vaccine in the younger population (30 years or younger) with MS, evaluating the occurrence of immediate relapses following vaccination. Very young patients (n = 21) with a median age of 18.7 years (interquartile range [IQR], 19.1-19.8) were compared to young patients (n = 71) with a median age of 26.5 years (IQR, 24.2-28.3). AEs were more frequent in the very young age group when compared to the young age group after both first and second doses, at rates of 76.2% and 80.9% vs 52.1% and 59.1%, respectively.³ 

For more coverage of ECTRIMS 2021, click here.

REFERENCES

1. Achrion A. Treatments in the context of MS: about DMT’s and SARS-CoV2. Presented at ECTRIMS Congress 2021; October 13-15; Virtual. Presentation ID 003.
2. Dreyer-Alster S, Dolev M, Menascu S, et al. COVID-19 vaccination in patients with multiple sclerosis, what we have learnt by May 2021. Presented at ECTRIMS Congress 2021; October 13-15; Virtual. Poster 187. 
3. Menascu S, Dreyer-Alster S, Dolev M, et al. Safety and efficacy of COVID-19 Pfizer-BNT162b2 m-RNA vaccine in young MS population. Presented at ECTRIMS Congress 2021; October 13-15; Virtual. Poster P190.