What vaccinations are safe for patients taking azathioprine and mesalazine (mesalamine)?

Vaccination Recommendations for Patients on Azathioprine and Mesalazine

Patients on azathioprine should receive all non-live vaccines but must avoid live vaccines due to the risk of vaccine-strain infections, while those on mesalazine alone can safely receive all vaccines including live ones.

Classification of Vaccines

Non-Live Vaccines (Safe for all patients on azathioprine and/or mesalazine)

• Influenza (inactivated/injectable)
• Pneumococcal vaccines
• Tetanus, diphtheria, pertussis
• Hepatitis A and B
• Human papillomavirus (HPV)
• Inactivated polio vaccine
• COVID-19 vaccines

Live Vaccines (Contraindicated with azathioprine, safe with mesalazine alone)

• Measles, mumps, rubella (MMR)
• Varicella (chickenpox)
• Herpes zoster (shingles)
• Yellow fever
• Oral typhoid
• Oral polio
• BCG
• Rotavirus

Vaccination Guidelines Based on Medication

Patients on Azathioprine

• Live vaccines are contraindicated due to the immunosuppressive effects of azathioprine 1
• Patients should receive annual inactivated influenza vaccine and pneumococcal vaccination with a booster after 5 years 1
• Response to non-live vaccines may be adequate but potentially diminished 2
• Timing considerations:
  • Live vaccines should be given at least 4 weeks before starting azathioprine 1
  • Live vaccines should be avoided until at least 3 months after stopping azathioprine 1

Patients on Mesalazine Only

• All vaccines including live vaccines are safe as mesalazine is not considered immunosuppressive 1
• Normal immune responses to vaccines are expected 3

Patients on Combination Therapy (Azathioprine + Mesalazine)

• Follow the more restrictive guidelines for azathioprine
• Live vaccines are contraindicated 1
• Non-live vaccines are safe but may have reduced efficacy 2

Special Considerations

Herpes Zoster (Shingles) Vaccination

• The recombinant zoster vaccine (RZV, non-live) is preferred for patients on azathioprine 1
• The live zoster vaccine (ZVL) is contraindicated for patients on azathioprine 1
• Exception: Live zoster vaccine may be considered in patients on low-dose azathioprine (≤3 mg/kg/day) without other immunosuppressants, but only after careful risk-benefit assessment 1

Pre-Travel Vaccinations

• Pre-travel consultation is essential for patients on azathioprine 1
• Yellow fever vaccine is absolutely contraindicated for patients on azathioprine 1
• Alternative prevention strategies should be discussed when live vaccines are contraindicated 1

Varicella Exposure

• Patients on azathioprine without history of chickenpox should seek immediate medical attention if exposed to varicella zoster 1
• Consider zoster immune globulin in susceptible patients exposed to chickenpox or shingles 1

Monitoring and Practical Advice

• Obtain vaccination history and update vaccinations before starting azathioprine whenever possible 1
• Document immune status for vaccine-preventable diseases before starting immunosuppression
• Consider measuring antibody titers to assess protection status for critical diseases
• Household members should receive inactivated rather than live polio vaccine to prevent orofecal transmission 1

Recent Evidence on Safety

While guidelines strictly contraindicate live vaccines in patients on azathioprine, recent small studies suggest that inadvertent administration of live vaccines to patients on immunosuppression has not resulted in serious adverse events 4, 5. However, these findings are preliminary and do not change the current recommendations against live vaccines while on azathioprine.

Remember that these recommendations are designed to maximize protection against infectious diseases while minimizing the risk of vaccine-related complications in patients with altered immune function due to medication.