Common Questions

What are immunizations?

Immunizations help keep you and your child from getting a disease. They contain medicine that causes the body to make antibodies. These antibodies can then recognize and fight the disease if you or your child is later exposed to it.

Immunizations are also called vaccines or vaccinations.

Why should my child get immunized?

Vaccines:

• Help prevent you or your child from getting dangerous diseases for which there are often no medical treatments.
• Help keep disease from spreading.
• Help protect people with weak immune systems, who may not be able to get vaccines. Their only protection is for others to get vaccinated so illnesses are less common.
• Have very few serious side effects.
• Often are needed before a child can attend school or daycare.
• Prevent days out of work or school due to illness or caring for a sick person.

Vaccines are the best way we have to prevent infectious diseases. A successful vaccine program depends on everyone getting vaccinated.

When should my child be immunized?

Childhood immunization schedules may vary by province and territory. Ask your doctor what shots your child should get.

Why do I have to use the government schedule? Can't I use my own schedule?

The schedule recommended by experts is designed to work best with a child's immune system at certain ages and at certain times. The schedule is set up so that your child gets the best protection possible at the earliest age possible from the fewest shots possible.

Experts review the schedules based on the best research available and change the schedules as needed.

A different schedule may not provide protection for your child. If shots are spread out or skipped, a child may get the disease during the delay.

Why does my child need so many doses to protect against one disease?

Your child gets as many shots as needed to give him or her full protection from a disease. This may be one shot only, or it may be several doses.

More than one dose may be needed because immunity may have to build up over time. You want the best combination of immediate and future protection for your child. This means that your child needs a certain amount of vaccine spaced apart at different ages. This builds the best protection.

Don't babies get natural protection from the mother?

During the last few weeks of pregnancy, mothers give their babies some protection against disease. But it is only for diseases that the mother is protected against. The protection the baby gets does not last long.

Haven't we gotten rid of most diseases children are immunized for?

Vaccinations in Canada have led to a sharp drop in diseases. Better living conditions have also helped, but they aren't enough to protect you from disease.

Remember that a vaccine gives your child protection from the disease. A vaccine does not get rid of the disease. The disease still exists, and if fewer children get immunized for a disease, the disease could come back.

And some diseases no longer found in Canada, such as polio, still exist in other countries. People who travel or move to Canada can bring these diseases into the country. So it's still very important to have your child immunized.

Is it okay to skip a shot when my child is sick?

On very rare occasions, your doctor may suggest waiting to have your child immunized. For example, you may need to wait when your child has:

• A history of serious allergic reaction to a vaccine.
• Severe vomiting or diarrhea, when dehydration is a concern.
• A serious illness, such as pneumonia, bronchiolitis, or a severe asthma attack.

But children usually can still get a shot even when they have a minor illness. This includes a cold or an ear infection. And children usually can still get a shot when they are taking antibiotics.

Talk to your doctor if you have any concerns about having your child immunized.

Vaccine Safety

Are vaccines safe?

Yes. Health Canada and the U.S. Food and Drug Administration (FDA) carefully evaluate all vaccines for safety. After a vaccine is approved, Health Canada, the FDA, the vaccine maker, and other agencies watch for any reports of rare or unexpected reactions. In some provinces, health professionals are required to report any reaction following an immunization to the Canadian Adverse Events Following Immunization Surveillance System (CAEFISS). Go to www.canada.ca/en/public-health/services/immunization/canadian-adverse-events-following-immunization-surveillance-system-caefiss… for more information about how vaccine safety is checked.

The risk of problems from a disease is much greater than the risk from the vaccine. Whooping cough, for example, still exists. This disease can cause a child to have severe breathing problems or seizures. It can lead to a hospital stay or even death. 

Do vaccines cause autism?

No. False claims in the news have made some parents concerned about a link between autism and vaccines. But studies have found no link between vaccines and autism.^{footnote 1, footnote 2}

What are the side effects of vaccines?

Most side effects from vaccines are minor, if they occur at all.

The area where the shot was given may be sore. And some children may be fussy or get a slight fever. Your doctor or pharmacist can explain the reactions that could occur.

Serious side effects are very rare. It's much more dangerous to risk getting the diseases than to risk having a serious reaction to the vaccines.

Isn't it dangerous to get more than one vaccine at a time?

No. Combined vaccines have no greater risk for side effects than a single vaccine does.^{footnote 3}

Some parents worry about their children getting several vaccines at the same time. They worry that a child's immune system can't handle all those vaccine organisms at the same time.

Getting more than one shot may seem like a lot for a child's body to handle. But babies have billions of immune system cells that are hard at work all the time, fighting the many thousands of germs they're exposed to every day.

More and more vaccines are being combined into a single shot, such as the measles-mumps-rubella shot. This means fewer shots need to be given. Even though the vaccines are combined, each gives the same protection as it would if it were given alone.