Vaccines are made of weak or dead viruses or bacteria that give our immune system key information to resist disease. When vaccines enter the body, our bodies respond by boosting production of proteins called antibodies. These antibodies help protect against infection.
Robert Hayashi, M.D., FAAP
Professor of Pediatrics, Division of Pediatric Hematology/Oncology, Washington University in St. Louis
Ann Marie Mojica, M.D., FAAP
Post-Residency Training Member, Hematology/Oncology, American Academy of Pediatrics
What is immunosuppressive therapy?
Certain types of medical treatment called immunosuppressive therapy can weaken the body’s ability to protect against infection. Examples include chemotherapy, corticosteroids, immunotherapy, and radiation therapy.
Children and teens may receive immunosuppressive therapy as part of their cancer treatment. Kids may also need immunosuppressive therapy after a bone marrow (hematopoietic stem cell) transplant, or for treatment of other health conditions, such as autoimmune disease, asthma, and inflammatory bowel disease.
Even if a child was immunized or vaccinated prior to the immunosuppressive therapy for their health condition, there is often a need to repeat immunizations to provide protection.
When should my child get their vaccines after immunosuppressive therapy?
Your child’s pediatric specialty doctor will work together with their pediatrician to decide when vaccines are necessary. Up-to-date guidelines for immunization following the end of immunosuppressive therapy can change over time, so it is important to speak with the doctors treating your child.
In general, though, immunization with vaccines starts 6-12 months after the end of immunosuppressive therapy. This gives your child’s immune system a chance to recover so it can respond to the vaccine by making protective antibodies. Getting the vaccines too early may lead to a poor response to the vaccine. However, delayed immunization with vaccines may put a child at risk for infections.
Is it OK to get some vaccines before or during immunosuppressive therapy?
Some vaccines may be recommended before immunosuppressive therapy, such as pneumococcal or meningococcal vaccines to prevent serious bacterial infection. Other vaccines are given during therapy against dangerous viral infections, such as the vaccine against influenza (flu) or COVID.
When are immunizations not helpful with treatment?
Certain immunizations, such as live virus vaccines, can only be given when the immune system is back to normal. Examples of live vaccines include measles, mumps, and rubella (MMR) and varicella (“chickenpox”).
Full recovery of the immune system can vary with the type of immunosuppressive therapy a child received. It may take up to two years after the end of immunosuppressive therapy to get these types of vaccines. Your doctor may order special blood tests to check your child’s immune system to help in deciding which vaccines to give when.
Remember, while there may be some changes to your child’s immunization schedule when they receive immunosuppressive therapy, there’s no need to worry. Your child’s care team will work with you and your pediatrician to discuss the latest recommendations to provide your child with the most up-to-date care.