Your child is starting treatment that will suppress the immune system. This will affect how your child’s body responds to routine immunizations that protect your child against disease.
This guide explains how different vaccines interact with immune-suppressing treatment. It also discusses special situations like travel to other countries. You will need to work with your child’s regular health care provider to make sure that your child is up-to-date on all necessary immunizations and to help keep your child healthy while taking immune-suppressing treatment.
If you have any questions, speak to your child’s doctor or the treatment team.
What causes a suppressed immune system?
The following treatments can all suppress the immune system:
Malnutrition can also suppress the immune system.
Inactivated or "killed" vaccines do not contain any live viruses or bacteria that can cause disease. This means they are safe for patients whose immune system is suppressed.
The main concern with these vaccines is that a suppressed immune system may not respond to them, so they may not work as well. Therefore, the goal with inactivated vaccines is to make sure that your child has had all of the necessary vaccines at least 2 weeks before starting immune-suppressing treatment.
Inactivated vaccines include:
For hepatitis B vaccine, your child’s doctor may need to take a blood test to find out if your child has responded to the vaccine.
If your child is already taking immune suppression treatment and there are no plans to stop the treatment, your doctor can give inactivated vaccines according to the regular schedule. In some circumstances, changes to the routine schedule may be needed.
Live vaccines contain live viruses or bacteria that can cause disease. Patients whose immune system is suppressed should not take live vaccines.
Your child should have any necessary live vaccines 4 to 6 weeks before starting immune-suppressing treatment.
Live vaccines include:
- measles, mumps and rubella (MMR)
- varicella (chickenpox)
- live influenza vaccine given as a nasal spray (FluMist)
If your child will be travelling
If your child will be travelling, speak to your child’s doctor at least 6 to 8 weeks beforehand. Make sure that all your child’s routine vaccinations are up-to-date, especially MMR, tetanus and pertussis (whooping cough).
Depending on where your child is travelling, the doctor may recommend other vaccines as well.
The following inactivated vaccines are safe to give to a child whose immune system is suppressed:
- typhoid (injectable)
- Japanese encephalitis
The following live vaccines are not safe to give to a child whose immune system is suppressed:
- yellow fever
- typhoid (oral)
- Bacillus Calmette-Guérin (BCG)
Your child’s doctor may also suggest consulting an infectious disease specialist or a travel medicine specialist.
Immunizing family members
If your child is taking immune-suppressing treatment, you and any family members who live in the same household should be vaccinated. This will help keep your child healthy.
However, some live vaccines work by causing a very mild form of the disease. For most people, this is completely safe, but people who have received these vaccines can pass germs to other people. This could make your child sick.
The following live vaccines are safe to give to family members:
- measles, mumps and rubella (MMR)
- yellow fever
- oral typhoid
The following live vaccines are safe with some restrictions:
- Chickenpox (varicella): About 5% of people who receive this vaccine develop a rash. If this happens, the child whose immune system is suppressed should avoid contact with this person. Contact your child’s doctor if this happens, as your child may need to take treatment to prevent infection.
- Rotavirus: It is possible that people who receive this vaccine may have live virus in their feces (stool). If your family members receive the rotavirus vaccine, wash hands thoroughly and often.
People who receive oral polio vaccine have live virus in their feces. Family members should not receive this vaccine. This vaccine is not used in Canada.
It is safe for family members to take all inactivated vaccines. These cannot be passed on to your child.
If your child has been exposed to an infectious disease
If your child has been exposed to an infectious disease, call your child’s doctor right away. Your child may need to have treatment to prevent infection.
Your child will need treatment after being exposed to any of the following diseases:
- chickenpox (varicella)
- hepatitis A
If your child is stopping immune suppression treatment
The effects of immune-suppressing treatment last for a while, even after your child stops taking it. After stopping treatment, your child’s doctor should wait at least 3 months before giving any immunizations. This should give your child’s immune system time to recover and respond well to the immunizations.
Sometimes, a longer time period may be needed for certain immune-suppressing treatments.
There may also be some instances when your doctor may want to give an inactivated vaccine earlier (i.e., tetanus exposure), although there may be a chance your child’s immune system will not respond to it.
It is important to discuss these exceptional cases with your doctor.
- Immune-suppressing treatment can make inactivated vaccines work less well and can make live vaccines cause disease.
- Your child should be up-to-date on all inactivated vaccines at least 2 weeks before starting immune-suppressing treatment.
- Your child should be up-to-date on all live vaccines at least 4 to 6 weeks before starting immune-suppressing treatment.
- Family members should be up-to-date on most vaccines, to help keep your child healthy.
- Work with your child’s doctor and the treatment team to make sure your child’s immunizations and immune-suppressing treatment work well together.