Drug Interaction Report

Abemaciclib and Typhoid Vaccine: Interaction Details

AI-assisted, pharmacist-reviewed · AI content regenerated Jul 11, 2026 · Source data updated Jul 10, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature

Typhoid Vaccine

Typhim VI® Vivotif Vivotif®
+

Abemaciclib

Verzenio Verzenio®
Dr. Brian Staiger, PharmD, BCPS
Medically reviewed by
Updated Jul 10, 2026
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Interaction severity
Contraindicated
These should generally not be used together.
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.

Of 128 documented Abemaciclib interactions, 12 are rated contraindicated — including this one.
Worried about symptoms right now? Contact your pharmacist or prescriber, or call Poison Control at 1-800-222-1222 (US). Call 911 for an emergency.
At a glance + Effects may be stronger
The Bottom Line
Do not get the live oral typhoid vaccine (Vivotif) while taking abemaciclib, because your weakened immune system could let the vaccine cause an actual infection. Ask your care team about the inactivated injectable typhoid vaccine as a safer alternative.

These two should not be used together right now. Abemaciclib (Verzenio) is a cancer medicine that can weaken your immune system, which is your body's defense against germs. The oral typhoid vaccine (Vivotif) is a live vaccine, meaning it contains weakened but living bacteria. In a healthy person, your immune system easily handles that weakened germ and builds protection. But if your defenses are lowered by abemaciclib, that live germ could actually cause the very infection the vaccine is meant to prevent.

The good news is this is very manageable. Please don't start or stop anything on your own. Talk with your oncologist or pharmacist, who can plan the safest way and timing to protect you against typhoid.

Contraindicated combination. Abemaciclib, a CDK4/6 inhibitor with antimitotic/immunosuppressive activity, can blunt humoral and cell-mediated immunity. The oral typhoid vaccine (Ty21a, Vivotif) is a live attenuated product; the injectable ViCPS (Typhim Vi) is not live.

  • Effect: impaired immune response permits the attenuated organism to cause active infection (vaccine-derived typhoid).
  • Mechanism: drug-induced immunosuppression, not a PK interaction.
  • Evidence: established; onset unspecified.
  • Management: avoid live typhoid vaccine during therapy. Per labeling, live vaccines may be considered only after immunocompetence is restored and chemotherapy has been discontinued for at least 3 months. Consider the inactivated ViCPS vaccine as an alternative if immunization is needed.
Onset
unspecified
Evidence
established
Severity
Contraindicated

What happens

An increased risk of infection by the live vaccine

Interaction Deep Dive

The use of typhoid vaccine is not advised for individuals who cannot generate a humoral or cell-mediated immune response, whether that inability arises from a congenital or an acquired immunodeficient condition, which encompasses those undergoing therapy with immunosuppressive or antimitotic agents2. A live vaccine may be given to patients with leukemia, lymphoma, or other malignancies provided their disease is in remission, their immunocompetence has been restored, and at least 3 months have elapsed since their chemotherapy was stopped1.

Why it happens (mechanism)

Decreased immune response allows live vaccine to produce infection

How to manage this interaction

Keep taking your abemaciclib as prescribed and do not receive the live oral typhoid vaccine while on it. This is a situation your care team can plan around.

  • Tell your oncologist and pharmacist if typhoid protection is needed (for example, before travel).
  • Your team may choose the inactivated (injectable) typhoid vaccine instead of the live oral one.
  • Live vaccines are generally only considered once your immune system has recovered and chemotherapy has been stopped for at least 3 months, as judged by your care team.
  • Report any fever, diarrhea, or signs of infection promptly.

Management is individual — confirm any change with your pharmacist or prescriber.

Common questions

Can I take Abemaciclib and Typhoid Vaccine together?

Do not get the live oral typhoid vaccine (Vivotif) while taking abemaciclib, because your weakened immune system could let the vaccine cause an actual infection. Ask your care team about the inactivated injectable typhoid vaccine as a safer alternative. Always confirm with your pharmacist or prescriber before making any change.

How serious is the Abemaciclib and Typhoid 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 is the Abemaciclib and Typhoid Vaccine interaction managed?

Keep taking your abemaciclib as prescribed and do not receive the live oral typhoid vaccine while on it. This is a situation your care team can plan around. Tell your oncologist and pharmacist if typhoid protection is needed (for example, before travel). Your team may choose the inactivated (injectable) typhoid vaccine instead of the live oral one. Live vaccines are generally only considered once… Management is individual — always follow your own care team's guidance.

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 Abemaciclib or Typhoid 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)

  1. Centers for Disease Control and Prevention (CDC): Vaccines & Immunizations: altered immunocompetence. Centers for Disease Control and Prevention (CDC). Atlanta, GA. 2024.
  2. Product Information: VIVOTIF(R) oral coated capsules, live typhoid vaccine ty21a oral coated capsules. Bavarian Nordic Inc (per Dailymed), Morrisville, NC, 2024. DailyMed
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This information is for education, not a substitute for professional medical advice. Do not start, stop, or change any medication without talking to your pharmacist or prescriber.