Does a breastfed infant whose mother is taking azathioprine (Imuran) 12.5-25 milligrams daily for autoimmune hepatitis require a modified vaccination schedule due to potential immunosuppressive effects of azathioprine in breast milk?

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Last updated: March 19, 2025View editorial policy

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From the Guidelines

No, a breastfed baby whose mother takes azathioprine 12.5-25mg daily for autoimmune hepatitis does not need to alter their vaccination schedule. The amount of azathioprine that passes into breast milk is minimal, with infants receiving less than 1% of the maternal dose, as noted in the British Association of Dermatologists' guidelines 1. This low exposure is unlikely to significantly suppress the baby's immune system or reduce vaccine effectiveness. Major medical organizations consider azathioprine compatible with breastfeeding at these doses. The baby's immune system remains capable of mounting appropriate responses to vaccines, including both inactivated and live vaccines according to the standard immunization schedule, as supported by general recommendations on immunization from the Advisory Committee on Immunization Practices (ACIP) and the American Academy of Family Physicians (AAFP) 1. While azathioprine is an immunosuppressant, the trace amounts in breast milk are insufficient to cause clinically significant immunosuppression in the infant. Regular pediatric follow-up is still recommended, but no special precautions regarding vaccinations are necessary in this situation. Key points to consider include:

  • The minimal amount of azathioprine in breast milk
  • The compatibility of azathioprine with breastfeeding as per medical organizations
  • The standard vaccination schedule for breastfed infants
  • The importance of regular pediatric follow-up.

From the Research

Immunization Schedule for Breastfed Infants

  • The provided studies do not directly address the question of whether a breastfed infant whose mother is taking azathioprine (Imuran) 12.5-25 milligrams daily for autoimmune hepatitis requires a modified vaccination schedule due to potential immunosuppressive effects of azathioprine in breast milk 2, 3, 4, 5, 6.
  • However, studies suggest that breastfeeding provides passive and likely long-lasting active immunity to infants, and that breast milk contains diverse immune-active factors that affect the ontogeny of the immune system in breastfed infants 4, 6.
  • The Advisory Committee on Immunization Practices (ACIP) recommends a standard immunization schedule for children and adolescents, with no specific modifications for breastfed infants whose mothers are taking immunosuppressive medications 5.
  • Some studies suggest that breastfed infants may have improved immune responses to vaccinations, although this is not universally agreed upon 4, 6.
  • There is no direct evidence to suggest that azathioprine in breast milk would require a modified vaccination schedule for breastfed infants, but this topic may require further research for a definitive answer.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Immunization of preterm infants.

Human vaccines & immunotherapeutics, 2015

Research

Breastfeeding provides passive and likely long-lasting active immunity.

Annals of allergy, asthma & immunology : official publication of the American College of Allergy, Asthma, & Immunology, 1998

Research

Immunology of breast milk.

Revista da Associacao Medica Brasileira (1992), 2016

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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