Immunizations and side effects from vaccines
Side effects
Some people question the safety of immunizations for children. Although minor discomfort sometimes follows vaccine injections, research does not support claims that immunizations put a child at any significant risk for harmful side effects. Health Canada and the Public Health Agency of Canada (PHAC) carefully evaluate all vaccines for safety. Health professionals voluntarily report serious health events following immunization to the Vaccine Associated Adverse Events Surveillance System (VAAESS). Only two vaccines—the 1976 swine influenza vaccine and the old rotavirus vaccine in 1999—have ever been recalled because of safety concerns.
Side effects from vaccines are generally minor, if they occur at all. Reactions may include a sore arm from the injection, a slight fever, and fussiness in children. More serious side effects occur very rarely. The risk of a serious complication from a disease is far greater than the risk from the vaccine.
Health Canada and the PHAC continue to study vaccines. Although the risk of problems from vaccines is already extremely low, these agencies watch for any reports of rare or unexpected reactions.
Exposure to mercury
Thimerosal, a mercury-containing compound, was once added to vaccines to prevent bacterial growth. In 1999, the U.S. Advisory Committee on Immunization Practices (ACIP) responded to concern about this additive's safety and set a goal to have it removed from all U.S.-manufactured vaccines. Unlike Canada, most of the routine childhood vaccinations used in the U.S. at that time contained thimerosal.
Even though recent studies have found no scientific proof linking autism or any other condition with thimerosal, all routinely recommended childhood vaccines manufactured for the Canadian market contain either no thimerosal or only trace amounts.1
In Canada, the only regular childhood vaccine that contains thimerosal is the hepatitis B vaccine, and it contains very small amounts far below the level that is considered to be safe. A new hepatitis B vaccine that contains no thimerosal is also available in Canada.2
| Author: | Alison Allen Debby Golonka, MPH | Last Updated: January 29, 2008 |
| Medical Review: | Michael J. Sexton, MD - Pediatrics Andrew Swan, MD, CCFP, FCFP - Family Medicine | |
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