Ministry of Health and Long-Term Care (Ontario)

Vaccines are one of the best medicines. Unlike many other medicines, they help prevent disease, which is always better than having people fall ill and need treatment. Over the past 100 years, vaccines have had a dramatic effect on our health and well-being. By reducing and — in one case, smallpox — eradicating a disease from the globe, they have changed the course of history.

http://www.health.gov.on.ca/en/common/ministry/publications/reports/
cmoh_14_vaccines/default.aspx