Melphalan and Yellow Fever Vaccine: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Yellow Fever Vaccine
Melphalan
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
An increased risk of infection by the live vaccine
Interaction Deep Dive
Immunosuppressed patients should not receive yellow fever vaccine or travel to yellow fever endemic areas. Exposure to yellow fever vaccine poses a risk of encephalitis or other serious adverse events1. Patients with leukemia, lymphoma, or other malignancies whose disease is in remission, who have restored immunocompetence, and whose chemotherapy has been discontinued for at least 3 months can receive a live vaccine 2.
Why it happens (mechanism)
Decreased immune response allows live vaccine to produce infection
Common questions
Can I take Melphalan and Yellow Fever Vaccine together?
An increased risk of infection by the live vaccine Always confirm with your pharmacist or prescriber before making any change.
How serious is the Melphalan and Yellow Fever Vaccine interaction?
It is rated contraindicated. These should generally not be used together.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How strong is the evidence for this interaction?
The evidence is graded "established". Well documented — supported by controlled studies or strong clinical data.
Questions for your pharmacist
- Does my dose of Melphalan or Yellow Fever Vaccine need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (2)
- Product Information: YF-VAX(R) subcutaneous injection, yellow fever vaccine subcutaneous injection. Sanofi Pasteur Inc (per FDA), Swiftwater, PA, 2016. DailyMed
- Centers for Disease Control and Prevention (CDC): Vaccines & Immunizations: altered immunocompetence. Centers for Disease Control and Prevention (CDC). Atlanta, GA. 2024.
Keep reading about Yellow Fever Vaccine
Keep reading about Melphalan
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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