COVID vaccine guidance for MS patients


The Canadian Network of MS Clinics has endorsed a COVID vaccination guidance document developed by the U.S. National MS Society (see links below). The advice is based on expert opinion due to a lack of data on the safety and efficacy of the COVID vaccine in the multiple sclerosis population and applies only to the mRNA vaccines (Pfizer, Moderna) currently available.

The guidance document recommends COVID vaccination for most patients with relapsing and progressive MS. Vaccination is especially encouraged in high-risk patients, including older individuals, Black and Hispanic populations, pregnant women and those with certain comorbidities (e.g. diabetes, hypertension, heart and lung disease, obesity). Vaccination is also advised for MS patients who have recovered from COVID-19. The document notes that the risks of COVID-19 outweigh any risk of an MS relapse due to the vaccine.

Clinicians should advise their MS patients to continue disease-modifying therapy (DMT) unless told otherwise. Discontinuation of some DMTs (e.g. natalizumab, fingolimod) can result in worsening disability.

The timing of COVID vaccination will depend on the individual patient’s risk of COVID and the current state of their MS. The group recommends that the DMT dosing schedule remain unchanged if there is a risk of MS worsening.

The following dosing adjustments may be considered for patients with stable MS:

  • First-line therapies (interferons, glatiramer acetate, teriflunomide, dimethyl fumarate): No change in dosing required.
  • S1P receptor agonists (fingolimod, siponimod, ozanimod): For currently-treated patients, no change to dosing when taking the vaccine. Delay treatment initiation for at least 4 weeks after receiving the second vaccine injection.
  • Cell-depleting therapies (cladribine, alemtuzumab): For currently-treated patients, the optimal timing of vaccination is at least 24 weeks after the last dose (minimum 12 weeks); do not re-dose until at least 6 weeks after the last vaccine injection. If initiating therapy, start the DMT at least 6 weeks after the second vaccine dose.
  • Anti-CD20 therapies (ocrelizumab, rituximab): For currently-treated patients, vaccinate at least 12 weeks after the last dose; do not re-dose for at least 4 weeks after the second vaccine dose. For new patients, schedule the first dose at least 4 weeks after the second vaccine injection.
  • High-dose steroids: Wait a few days after steroid administration before administering the vaccine.
  • NSAIDs: Avoid these medications for 24 hours before and after vaccination, if possible.

A concern is that some provinces are now recommending a 90-day delay before administering the second vaccine injection, which may complicate DMT dosing. It should also be noted that MS patients are not considered to be a high priority group for COVID vaccination unless they are aged >70 years or live in a senior care home or other chronic-care setting. As of January 21, an estimated 682,141 vaccine doses had been administered in Canada, representing 0.9% of the population.


Canadian Network of MS Clinics: Note that the U.S. guidance has not been adapted for Canada and links in the article may not apply. Recommendations for policy-makers.

Health Canada:

COVID vaccine tracker:

National MS Society:

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