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Myths Vs. Facts about vaccines/immunizations

Myth vs. Fact

MYTH #1: Vaccines can cause serious side effects.1

FACT: Vaccines are among the safest tools of modern medicine. In Canada, severe side effects are extremely rare. Most side effects are minor and temporary – like a mild fever or sore arm. The dangers of vaccine-preventable diseases are much graver than the risk of a serious reaction to vaccines.

MYTH #2: Vaccines don’t work.1

FACT: Sometimes people who have been immunized still get sick. This doesn’t mean that vaccines don’t work. No vaccine is 100% effective, and because each person is different, a small percentage of people will not develop enough immunity to protect them from disease. But vaccines have been proven to work in the majority of people who have been vaccinated.

MYTH #3: The MMR vaccine causes autism.1

FACT: The measles, mumps, rubella (MMR) vaccine does not cause autism. Extensive medical research has shown there is no link between the MMR vaccine and autism.

MYTH #4: Vaccines are unnecessary because the diseases they prevent are uncommon in Canada.1

FACT: Vaccine-preventable diseases are now uncommon in Canada because our immunization programs have worked. Experiences in other countries have shown that if immunization is stopped, diseases come back.

MYTH #5: Multiple vaccines given all at once can overwhelm the immune system.1

FACT: Multiple injections given all at once and combination vaccines will not overwhelm the immune system. Exposure to the few antigens in combination vaccines is easily handled by our immune system.

In Canada, before any vaccine is used in combination with other vaccines, extensive testing makes sure the combination is safe for use in children. Combination vaccines also mean fewer needles.

MYTH #6: Vaccines contain toxic substances.1

FACT: The main ingredient in vaccines is a weakened or killed version of the particular germ that the vaccine is intended to protect us from. Vaccines do NOT contain the germ that makes you sick.2 The safety of each vaccine is continuously monitored and tested around the world and in Canada. 1

  1. Public Health Agency of Canada. Frequently asked questions. http://www.phac-aspc.gc.ca/im/vs-sv/vs-faq-eng.php .
    Accessed March 29, 2016.
  2. Public Health Agency of Canada. What is a vaccine and how does it work? http://www.phac-aspc.gc.ca/im/vs-sv/vs-faq01-eng.php. Accessed February 28, 2014.