Most people know that children being treated for cancer have a suppressed immune system and are at extra risk for vaccine-preventable diseases.

That’s one of the reasons that it is important for everyone to be vaccinated, so that herd immunity levels of protection can protect those who can’t get vaccines.
Vaccines After Cancer and Chemotherapy
But what happens after they complete their cancer treatments?
“The interval until immune reconstitution varies with the intensity and type of immunosuppressive therapy, radiation therapy, underlying disease, and other factors. Therefore, often it is not possible to make a definitive recommendation for an interval after cessation of immunosuppressive therapy when inactivated vaccines can be administered effectively or when live-virus vaccines can be administered safely and effectively.”
Red Book on Immunization in Immunocompromised Children
After they complete therapy for cancer, whether it is chemotherapy or a bone marrow transplant, many children need to get extra vaccines.
In the UK, for example, 6 months after completing “standard antileukemia chemotherapy,” children get a booster dose of DTaP, IPV, Hib, MenC, and MMR.
Why just a single booster dose?
Because most kids can continue to get non-live vaccines on schedule while they are getting standard chemotherapy. They get a booster dose when they finish chemotherapy because those vaccine doses they got while receiving treatment might not be as effective as usual and typically don’t count as valid doses.
Of course, if they were missing any doses, then they might need extra doses to catch up too.
“Three months after cancer chemotherapy, patients should be vaccinated with inactivated vaccines and the live vaccines for varicella; measles, mumps, and rubella; and measles, mumps, and rubella-varicella according to the CDC annual schedule that is routinely indicated for immunocompetent persons.”
2013 IDSA Clinical Practice Guideline for Vaccination of the Immunocompromised Host
In contrast to those getting standard chemotherapy, if treatment involved a hematopoietic stem cell transplant (HSCT), then these children are essentially revaccinated:
- beginning at 6 months after the HSCT, they should get 3 doses of DTaP if they are less than 7-years-old vs a dose of Tdap and 2 doses of Td if they are already 7-years-old
- beginning at 3-6 months after the HSCT, they should get 3 doses of Prevnar
- beginning at 6-12 months after the HSCT, they should get 3 doses of Hib
- beginning at 6-12 months after the HSCT, they should get 3 doses of hepatitis B, followed by postvaccination anti-HBs titer testing
- beginning at 6-12 months after the HSCT, they should get 3 doses of IPV
- beginning at 6-12 months after the HSCT, they should get 2 doses of a meningocococcal vaccine (if they are already 11 to 18 years old)
- beginning at 6-12 months after the HSCT, they should get 3 doses of HPV vaccine (if they are already 11 to 26 years old)
- beginning at 12 months after the HSCT, one dose of the Pneumovax vaccine
- beginning at 24 months after the HSCT, two doses of MMR
- beginning at 24 months after the HSCT, two doses of the chicken pox vaccine
- a yearly flu shot
Why not just check titers instead of repeating all of those vaccines?
“protective” concentrations or titers in this population may not be as valid as in healthy children, leaving open the question regarding what levels to use as the basis for revaccination. Furthermore, there are some vaccines for which no serological correlate of protection exists (e.g., pertussis) or for which, in routine practice, it is too difficult to have levels measured (e.g., polio).
Soonie R. Patel et al. on Revaccination of Children after Completion of Standard Chemotherapy for Acute Leukemia
In Canada, they used to check titers at 1, 3, and 5 years after the end of chemotherapy and just vaccinate when titers dropped, but they switched to giving all kids a booster dose, as it works better.
What will your child’s immunization look like after completing treatment for cancer?
Although the specific recommendations will come from your child’s treatment team, they will likely look something like the guidelines included here.
What to Know About Vaccines After Cancer and Chemotherapy
Kids often have to get revaccinated, or at least get booster doses of their vaccines, after completing treatment for cancer.
More on Vaccines After Cancer and Chemotherapy
- Vaccinations for cancer patients: What to know
- Practical vaccination guidelines for children with cancer
- Revaccination of Children after Completion of Standard Chemotherapy for Acute Leukemia
- Pediatric Oncology: Vaccination After Therapy
- 2013 IDSA clinical practice guideline for vaccination of the immunocompromised host.
- CDC – Recommendations of the Advisory Committee on Immunization Practices (ACIP)
- CDC – Altered Immunocompetence (ACIP)
- AAP – Immunization in Immunocompromised Children (Red Book)
- Vaccination During Cancer Treatment
- Immunisation of the Immunocompromised Child Best Practice Statement (UK)
- Post-HSCT immunization (Canada)
- My son has cancer. He can’t go into day care because of unvaccinated children.
- A Boy Who Had Cancer Faces Measles Risk From The Unvaccinated
- To the Parent of the Unvaccinated Child Who Exposed My Family to Measles
- Did Children’s Minnesota Expose Cancer Patients to Measles?
- Children with cancer: stories from the 2011 measles outbreaks
- Chickenpox hits young cancer patient, despite vaccination
- B.C. parent speaks out about vaccinations after nearly losing a child to Chickenpox
- CDC – Managing People at Risk for Severe Varicella