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Do vaccines always work?...
Do vaccines always work?
Vaccines do work; however, individual responses to vaccines depend on many factors (type of vaccine, individual's age and immune system, etc). The Canadian Immunization Guide outlines the effectiveness of each vaccine approved in Canada. After the approval of a vaccine, research monitors the efficacy of vaccines (how well the vaccine works). At the individual level, vaccines protect the immunized person against the specific disease; at a population level, vaccines reduce the number of new cases of the disease in the population.
If you have further questions about your health and vaccines, please speak with your health care provider.