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Frequently Asked Questions About Immunization

Do you have questions about immunization in Halton Region? Learn about immunization, specific vaccines, how they involve infants and school attendance.

General information

Are the materials used in immunizations safe?

Canada has very strict guidelines for making vaccines, which include many safety tests carried out by Health Canada.

Certain materials - such as formaldehyde and aluminum - are used to kill bacteria and make vaccines as effective and safe as possible. The levels used in vaccines are lower than what a child would be exposed to on a day-to-day basis.

Is natural immunity better than immunity from immunization?

No, because children who are not immunized are at risk of becoming infected with diseases before their body is able to fight them.

Immunization (which is made up of parts of weak or dead viruses or bacteria) works by triggering the body’s immune system to make the proper immunity (memory) cells. Therefore, when germs enter the body at a later time, the memory cells kill the germs before they can infect the body. Vaccines are far safer than getting the disease.

Why do I need to immunize my child if the diseases they are getting immunized against no longer exist in Canada anymore?

These diseases no longer exist in Canada because our immunization programs have protected many Canadians from certain diseases, making it very hard for them to spread. This builds a circle of protection around a whole community, and protects those who cannot be immunized (e.g., for medical reasons).

Specific vaccines

Can the measles-mumps-rubella (MMR) vaccines cause autism?

There is no difference in the rate of autism between immunized and unimmunized children. Evidence-based reviews and research studies involving millions of children have found no connection between immunization and autism.


Will multiple immunizations at one visit overwhelm my baby’s immune system?

No, multiple immunizations protect your baby against multiple diseases as early as possible. We all come into contact with millions of germs a day, so the immune system will easily handle exposure to antigens (made up of parts of weak or dead viruses or bacteria) in multiple immunizations.

I am breastfeeding. Is that enough to protect my child?

Breastfeeding gives babies a great start, but it will not protect them against all the specific diseases that immunization prevents.

If my child it teething, or has a cold, is it safe to get all their shots?

Yes, your child’s immune system works so well that they can get all their shots, even if they are teething, have a fever, diarrhea or ear infection, or are taking antibiotics.

School attendance

Will my child be suspended?

Halton Region Public Health is continuing to work with the Ministry of Health on the enforcement of mandatory vaccines under the Immunization of Students and Pupils Act (ISPA). However, due to the unforeseen circumstances brought on by COVID-19, suspensions under ISPA will not be enforced during the 2022/2023 school year. Vaccine education sessions are not available at this time, and therefore Halton Region Public Health is not currently accepting submissions for non-medical exemptions. Please check our Vaccine Exemption for Children webpage regularly for updates.

I gave my child's immunization records to the school when they registered. Why is the Health Department asking for it again?

The school collects and forwards immunization records to Halton Public Health only at the time of initial registration. After registration, parents are responsible for updating their child’s immunization records with the Health Department every time the child is vaccinated.

As your child gets older, there are additional immunizations and doses of vaccine required for them to be completely immunized for their age.

I think that my child has received all his/her immunizations at the doctor's office, but I can't remember. What should I do?

Check with your healthcare provider to make sure that your child has had all the vaccines needed to attend school. Don’t forget to report all immunizations to the Health Department. Your doctor’s office does not do this for you.