Is the COVID vaccine safe for patients with myasthenia gravis (Myasthenia Gravis, MG)?

COVID-19 Vaccination in Myasthenia Gravis Patients

Patients with myasthenia gravis should receive COVID-19 vaccination, as the benefits substantially outweigh the risks, and COVID-19 infection itself poses a significantly greater threat to MG patients than vaccination. 1, 2

Safety Profile of COVID-19 Vaccines in MG

The evidence strongly supports vaccination safety in MG patients:

• COVID-19 vaccines are well-tolerated in patients with stable, well-controlled MG, with no increased risk of myasthenic crisis following vaccination. 2

• In a prospective study of 91 MG patients receiving mRNA vaccines, none experienced myasthenic crisis, and only 2 patients (2.2%) developed mild deterioration that resolved without intervention. 2

• The most common adverse effects are typical vaccine reactions: injection-site pain, fatigue, myalgia, chills, fever, and headache—all transient and self-limited. 2

• Across multiple studies involving 1,347 MG patients, the vast majority tolerated vaccination without significant MG exacerbation. 3

Risk-Benefit Analysis: COVID-19 Infection vs. Vaccination

The risk of COVID-19 infection far exceeds vaccination risks:

• MG exacerbation rate following COVID-19 infection is 40%, compared to only 8.7% following vaccination. 4

• During the alpha and delta waves, unvaccinated generalized MG patients had a 26.7% mortality rate from COVID-19, compared to 0.96% in the general population. 4

• In one Italian cohort, 44% of unvaccinated MG patients who contracted COVID-19 died from respiratory complications. 5

• All vaccinated MG patients who contracted COVID-19 during the omicron wave had mild disease, with no severe outcomes or deaths. 4

Vaccination Recommendations by Disease Status

Stable MG (MGFA Class I-II)

• Vaccinate immediately regardless of immunosuppressive therapy status. 1, 6
• Both mRNA vaccines (BNT162b2, mRNA-1273) and other vaccine types are appropriate. 1, 2
• Complete the full vaccine series even if mild, non-serious adverse events occur after the first dose. 1

Active but Non-Life-Threatening MG

• Proceed with vaccination without delay. 1
• While vaccination is ideally performed during well-controlled disease, patients should not defer vaccination waiting for optimal disease control. 1

Life-Threatening MG (ICU-level disease)

• Defer vaccination until disease is better controlled. 1

Timing Considerations with Immunosuppressive Therapies

Anti-CD20 Therapy (Rituximab)

• Ideally vaccinate at least 6 months after the last rituximab dose to optimize antibody response. 1, 7
• If disease is active, prioritize immunosuppressive therapy over optimal vaccine timing. 1

High-Dose or Long-Term Corticosteroids

• Delay vaccination 4-6 weeks after treatment cessation when feasible. 1, 7
• If continuing steroids, vaccinate anyway—do not withhold vaccination. 2

Other Immunosuppressants

• Vaccination can proceed while on standard immunosuppressive regimens (azathioprine, mycophenolate, etc.). 2
• 79.1% of successfully vaccinated MG patients in one study were taking one or more immunosuppressants. 2

Practical Implementation

mRNA vaccines (Pfizer/BioNTech, Moderna) are preferred when available, though other vaccine types have shown acceptable safety profiles. 1, 2

• Complete the full two-dose primary series according to standard schedules. 1
• Administer booster doses following national guidelines. 7, 4
• No preference exists between available mRNA vaccines. 1

Monitor patients for 4-6 weeks post-vaccination for any MG symptom changes, though significant exacerbations are rare. 3, 6

• Most reported exacerbations are mild and resolve within days without intervention. 6
• Patients over 65 years develop fewer adverse effects. 2

Critical Caveats

Do not routinely order antibody testing post-vaccination to assess immunity, as this does not guide clinical management. 1

Household members and close contacts should be vaccinated to create a "cocooning effect" protecting the MG patient. 1

Continue all public health measures (masking, distancing) even after vaccination, as immunosuppressed patients may have blunted vaccine responses. 1

Live-attenuated vaccines remain contraindicated in patients on immunosuppressive therapy, but COVID-19 mRNA vaccines are not live vaccines. 7

The theoretical risk of vaccine-induced MG exacerbation is substantially lower than the proven risk of COVID-19-induced respiratory failure and death in MG patients. 4, 5