Live Attenuated Vaccine Administration in Children Treated With Methotrexate or Dupilumab.

Background And Objectives: A wholesale recommendation against use of live virus vaccines in patients treated with any medication classified as an immunosuppressant has been based on global theoretical concerns rather than clinical outcomes for specific drugs.

Methods: A retrospective search of electronic medical records identified patients seen by the Allergy and/or Dermatology services between 2017 and 2023 at a pediatric tertiary center who received a live attenuated vaccine during the 6 week interval prior to the first prescription for methotrexate or dupilumab until 6 weeks after the last prescription for either medication. Individual charts of identified patients were manually reviewed for evidence of adverse events.

Results: The search identified 313 pediatric patients treated with dupilumab and/or methotrexate during the 7-year interval. Five of these patients received the combination measles, mumps, rubella, and varicella (MMRV) vaccine while on dupilumab and 4 while on methotrexate. Manual chart review was without evidence of adverse events for up to 6 months after immunization.

Conclusions: This retrospective search identified a small number of pediatric patients immunized with the live attenuated MMRV vaccine during concomitant treatment with dupilumab or methotrexate. No associated adverse events were identified. Further investigation is needed to establish the safety and efficacy of live vaccines in patients treated with these immunomodulating agents.