Vaccine Safety

Overview

Vaccines are safe. Health Canada and the U.S. Food and Drug Administration (FDA) carefully check 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 most 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.html for more information about how vaccine safety is checked.

The risk of a serious problem from a disease is far greater than the risk from the vaccine. For example, 1 child in a group of 20 unvaccinated children may die from diphtheria disease. But only 1 child in a group of 14,000 vaccinated children may have side effects after getting the DTaP vaccine. And that child would recover.^{footnote 1}

Vaccines are safe even if you or your child:

• Has or is recovering from a minor illness, such as a cold or an ear infection.
• Has a slight fever.
• Has had recent exposure to someone with a disease that is easily spread from person to person.
• Had a mild reaction from a previous injection, such as redness at the site of the shot or a slight fever.
• Is currently taking antibiotics.
• Has had mild allergies or seizures or has a family history of such problems.
• Has had allergic reactions to penicillin or other antibiotics (except for a history of severe reactions to neomycin or streptomycin).

Vaccines are also safe for premature infants.

Certain vaccines are safe during pregnancy. But some vaccines are not given during pregnancy. Ask your doctor which vaccines you need before you get pregnant and during pregnancy.

Getting more than one vaccination at a time

Getting more than one vaccine at a time is not dangerous.

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 vaccines 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.

After careful study, more and more vaccines are being combined into a single shot, such as the measles-mumps-rubella shot. This means you or your child needs fewer shots. Even though the vaccines are combined, each gives the same protection as it would if it were given alone.

Health Canada and the U.S. Advisory Committee on Immunization Practices recommend that children get all of the vaccines needed at their age in one doctor visit.

Combination vaccines include:

• Hepatitis B/Haemophilus influenzae type b.
• Diphtheria, tetanus, pertussis/Polio.
• Diphtheria, tetanus, pertussis/Polio/Hepatitis B.
• Diphtheria, tetanus, pertussis/Polio/Haemophilus influenzae type b.

Health Canada, the U.S. Centres for Disease Control and Prevention (CDC), and the U.S. Food and Drug Administration (FDA) continue to study vaccines. The risk of problems from vaccines is already extremely low. But these agencies watch for any reports of rare or unexpected reactions.

Talk to your doctor if you have concerns about the safety of vaccines.