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Immunization "Catch-Up" for Children Who Have Not Been Fully Immunized

Immunization (vaccines) protect your child against several serious, life-threatening infectious diseases. Your child should have "shots" according to the schedule recommended for your province, state, or country. Your child should also have a written record of which immunizations she has had and when.

Children who are new to Canada - immigrant, refugee, or adopted children - may not be vaccinated according to Canada's standards.

Canada's immunization schedule

In Canada, children normally receive vaccines at the following ages:

  • 2 months
  • 4 months
  • 6 months
  • 12 months
  • 15 months
  • 18 months
  • 4 to 6 years
  • 9 to 13 years
  • 14 to 16 years

 If your child has not been fully immunized

There are several reasons why children may not be fully immunized, such as:

  • missing one or more appointments
  • illness during the time they should have had a shot
  • being new to Canada: immigrant, refugee, and internationally adopted children may not have been immunized according to Canada’s schedule, or some vaccines may not be available where they come from

These children could be at risk of catching a harmful disease. If your child has not been fully immunized for any reason, talk to your doctor or other health care provider about making sure that her shots are up to date.

If your child has not been in your care since birth, it may be hard to determine her vaccine history. If your child has a written immunization record, show it to your doctor.

All children who have not been fully immunized, or who do not have a written immunization record, should start receiving vaccines on a routine schedule. This schedule depends on your child’s age. Speak to your doctor about what is right for your child.

It is always preferable to give a vaccine if unsure of the child's history. There is no harm to repeating any immunization, unless the child has had an allergic reaction to the vaccine in the past, or has an underlying disease that could affect the response to the vaccine.

Sometimes your doctor will do a blood test to see which antibodies are missing from your child’s blood. This will tell him which vaccines your child still needs. 

As with all vaccines, if your child has a severe illness or a fever, you may need to wait to give your child a vaccine.  

Reasons not to vaccinate

If any of the following conditions apply to your child, talk to your doctor before getting your child vaccinated:

  • Your child had an allergic reaction to a previous vaccination.
  • Your child has seizures or serious neurological disease.
  • Your child has poor immunity. Children with weak immune systems should not be given live virus vaccines such as chickenpox or MMR. Because live virus vaccines live and divide within the person vaccinated, they can cause the actual disease if the immune system is very weak.
  • Your child has egg allergies. Children who have a severe allergy to eggs should not receive the influenza vaccine. However, children who are allergic to eggs can receive all routine immunizations. Although the measles and mumps vaccines are grown in chick cells, the egg proteins are removed from these vaccines and the vaccines can be given without having your child skin tested for an egg allergy.

Key points

  • Immunization protects your child against disease.
  • In Canada, children normally receive vaccines according to a schedule.
  • There are several reasons why a child may not be fully immunized, including illness or being new to Canada.
  • If your child has not been immunized according to the normal schedule, speak to your child’s doctor.
  • Your child should have a written immunization record.

Sheila Jacobson, MBBCh, FRCPC


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Immunization of Children and Adults with Inadequate Immunization Records. Last accessed March 2010.  

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