Multinational Study Highlights COVID-19 Vaccine Safety in MS

As COVID-19 variants continue to evolve, vaccination remains a critical component of care for individuals with multiple sclerosis (MS), especially those receiving immunosuppressive therapies, according to a new review highlighting the latest evidence supporting vaccination safety and effectiveness in this vulnerable population.¹

The multinational team of experts aimed to clarify lingering concerns around vaccine timing, disease-modifying therapies (DMTs), and long-term protection while also offering practical guidance for US health care providers and policymakers.

The review, published in Neurology Neuroimmunology & Neuroinflammation, emphasized that vaccination remains one of the most effective tools to prevent severe COVID-19 outcomes—especially for patients receiving DMTs. Although earlier studies produced mixed messages about infection risks among patients with MS (PwMS), this analysis clarified that the benefits of vaccination significantly outweigh the risks, even in patients on immunosuppressive regimens.

According to the National Multiple Sclerosis Society, PwMS are not inherently at greater risk for contracting COVID-19 or experiencing severe illness. However, the risk increases for those with factors such as older age, Black race, male sex, obesity, progressive MS, or additional chronic conditions, or who use specific DMTs like anti-CD20 treatments.²

“COVID-19 vaccination should be administered following national recommendations and especially also in PwMS, [several individual and health] factors…should be taken into account. Comparatively, these factors are also very important for those who are vaccine skeptical because the risk of potential COVID-19 disease may be significantly increased in at-risk individuals,” the authors emphasized.¹

Researchers reviewed a wide body of clinical trial data, observational studies, and registry information. They also aligned their findings with recommendations from the CDC, the European Medicines Agency, and leading international MS organizations. Notably, mRNA and vector-based vaccines have continued to show strong efficacy against severe disease, including with the Omicron strain and its subvariants, and have maintained favorable safety profiles in PwMS.

Rare adverse events—such as myocarditis, pericarditis, vaccine-induced thrombotic thrombocytopenia, and Guillain-Barré syndrome—were most often seen in young men and remained uncommon. Reassuringly, vaccination did not appear to increase the risk of MS relapse or exacerbate disease activity.

One key insight for managed care decision-makers is how certain DMTs, particularly B-cell–depleting therapies like anti-CD20 agents, may blunt the antibody response to vaccines. However, patients still typically generate a strong cellular immune response, which contributes meaningfully to protection. The review also pointed to hybrid immunity—prior infection plus vaccination—as offering the most robust and durable defense, supporting the use of booster programs.

To optimize outcomes, the authors recommended aligning vaccination timing with DMT dosing schedules where feasible. For example, spacing out vaccinations from cyclic DMT administration could improve the immune response—an important consideration for neurologists and care teams balancing disease control with COVID-19 protection.

The report urged continued education for both providers and patients about vaccine safety while also encouraging policies that prioritize timely access to boosters. For payers and population health leaders, these findings reinforce the value of integrating COVID-19 vaccination strategies into MS care pathways—without delaying or compromising disease-modifying treatment.

The authors concluded, “Overall, vaccination against COVID-19, especially for PwMS, represents a very important step in combating this ongoing pandemic, besides other actions.”

References

1. Monschein T, Zrzavy T, Rommer PS, et al. SARS-CoV-2 vaccines and multiple sclerosis: an update. Neurol Neuroimmunol Neuroinflamm. 2025;12(3):e200393. doi:10.1212/NXI.0000000000200393

2. Multiple sclerosis and COVID-19. National Multiple Sclerosis Society. Updated June 2025. Accessed July 7, 2025. https://www.nationalmssociety.org/managing-ms/living-with-ms/diet-exercise-and-healthy-behaviors/vaccination/covid