Get the facts about immunization

Know the facts about immunization so you can make informed decisions about your health and your children's health.

On this page

About vaccines

Vaccines are made with a tiny amount of dead or weakened germs. They help the immune system learn how to protect itself against disease. Vaccines are a safe and effective way to keep your child from getting very sick from the real disease.

Most vaccines are given by an injection (a needle) into your child's upper arm or thigh. Some vaccines can be given orally (by mouth) or nasally (sprayed into the nose).

Your child can safely get more than one vaccine at a time. Some vaccines protect against several diseases in a single shot, while others are given separately.

The immune system

The immune system is a special network in the body that protects you from germs, like bacteria and viruses that cause diseases. Through a series of steps called the immune response, the immune system learns how to recognize germs. This is so it can fight them if your child is exposed to them in the future.

Your child is exposed to thousands of germs daily home, at daycare or in the grocery store.  Most of these germs are harmless and are easily handled by your child's immune system. But some germs can make your child very sick.

Thanks to vaccination, your child's immune system learns how to recognize harmful germs. Vaccines help your child to develop the necessary defenses to fight disease, and to stay healthy!

Vaccines work

The dead or weakened germs in vaccines help your child's immune system make tools like antibodies and immune memory. Together, these tools will help your child recognize and fight off the germs if exposed to them in the future.

Most children are fully protected after they are vaccinated. This means that they will never get serious vaccine-preventable diseases.

In rare cases, children who are immunized can still get the disease. This is because they only get partial protection from the vaccine.  This is more common in children with a health problem that affects their immune system. They may develop mild symptoms if they are exposed to a disease, but will not suffer serious complications.

Vaccines are safe

Vaccines are safe and provide important benefits for your children's health throughout their lives.

Many parents with young children have not seen serious vaccine-preventable diseases. They may not know how serious the diseases are. As a result, parents may worry more about the side effects of vaccines than the diseases they prevent.

Like all medicines, vaccines need to go through a series of tests before they can be used in Canada. Several systems are in place to monitor the creation, the use and the safety of vaccines. Vaccine reactions are reported by health care providers to local public health authorities. This is to make sure unusual or unexpected reactions can be dealt with quickly.

Vaccination versus the actual disease

Some people believe that getting the actual disease is safer than the vaccine.  Your child's natural immune system has no problem handling the weak or dead germs in a vaccine. Your child may have a mild fever or a sore arm after vaccination. These side effects only last a few days and should not disrupt daily activities.

However, if an unvaccinated child catches the real disease, the result can be serious, or even fatal. This is because active germs multiply quickly, and your child's immune system is not prepared to defend itself.

Where to get more facts

It is important to get the facts about vaccination from reliable sources. Talk to a trusted health care provider about your child's vaccinations. Trusted sources include your:

  • doctor
  • nurse
  • pharmacist

For more information

The internet has a lot of helpful information about vaccines and vaccine-preventable diseases. However, there is also misinformation on the web. Some of it can be harmful if used to make health decisions. Here are some websites you can trust to find information on vaccination:

Report a problem or mistake on this page
Please select all that apply:

Privacy statement

Thank you for your help!

You will not receive a reply. For enquiries, contact us.

Date modified: