Vaccines and MS – are they still effective?

Vaccines and MS – are they still effective?

1000 662 Shawn Haigh

During the coronavirus disease 2019 (COVID-19) pandemic, vaccines have been at the forefront of the public consciousness. This is especially true for individuals with multiple sclerosis (MS), as some may wonder whether their condition prohibits them from getting vaccinated. Moreover, the effectiveness of a vaccine in an individual with MS may come into question, especially when the patient is being treated with a disease-modifying drug (DMD).


Should MS patients get vaccinated?

With the prevalence of vaccine hesitancy and the “anti-vaccination” movement, especially in some Western countries, it should be noted: there is a consensus among experts that MS cannot be caused by vaccines.1 This applies to both inactivated vaccines, like the one for influenza, and live attenuated vaccines, like the one for measles.1 While there is no evidence of increased risk for MS or increased relapse rates after vaccination, there is evidence that infections can trigger relapses in MS.1 As such, prevention of infection in individuals with MS is beneficial.1

There are also concerns that MS may reduce the effectiveness of vaccines. However, the American Academy of Neurology (AAN) instructs clinicians to recommend that patients with MS follow all local vaccine standards, unless there are specific contraindications.2 The same guidelines suggest that live attenuated vaccines should not be used in people with MS who are currently taking or have recently taken immunosuppressive/immunomodulating (ISIM) therapies.2


Vaccine effectiveness and MS treatment

Studies have shown that patients with MS can develop a protective immune response after the influenza vaccine. However, patients taking certain DMDs to treat MS may have an increased risk of infection after vaccination.3 The patient’s likelihood of developing an immune response may also be altered by the use of DMDs.3

During a study which aimed to determine the onset of action of cladribine, an oral DMD for patients with highly active relapsing MS, some patients received vaccinations during the course of the trial.3 This presented an opportunity to investigate the vaccine response, which would produce much-needed vaccination data in light of the COVID-19 pandemic.3

Blood samples were taken from 15 patients with relapsing MS treated with cladribine who received either the varicella-zoster virus (VZV) vaccine (n=3) or the influenza vaccine (n=12).3 It was found that both vaccines resulted in immunity (against VZV or influenza), even when they were given around the same time as treatment with cladribine.3 Seroprotective antibody levels against VZV and influenza were maintained or increased for at least six months, independent of lymphocyte counts measured at the time of vaccination.3


What about the COVID-19 vaccine?

A study from early 2021 found that untreated individuals with MS vaccinated against COVID-19 developed a protective immune response against SARS-CoV-2 similar to that of vaccinated people without MS.4 Additionally, MS patients had similar rates of adverse events after receiving the BNT162b2 mRNA vaccine (Pfizer, BioNTech) compared with healthy vaccine recipients.5 Untreated MS patients should discuss the COVID-19 vaccine with their healthcare provider.5 Those on certain drugs should additionally discuss vaccination, as it is sometimes recommended to wait months after treatment to get vaccinated.4


Final thoughts

Managing personal health during a global pandemic can be stressful, and the complications that come with MS only add to that stress. Staying informed and communicating with your healthcare provider can be powerful tools that can provide peace of mind during these difficult times. The studies and expert opinions outlined above are only a fraction of the information available to help individuals with MS come to an informed decision about getting vaccinated.


  1. Zrzavy T et al. Front Immunol. 2019;10:1883
  2. Farez M et al. Neurology. 2019;93:584-594
  3. Roy S et al. Presented at the ACTRIMS 2021 Virtual Congress. 2021
  4. Achiron A et al. Ther Adv Neurol Disord. 2021;14:1–8
  5. Achiron A et al. Mult Scler J. 2021:1–7
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