The History of Vaccines: A Glance Behind and a Look Ahead

Vaccines are about much more than protecting the individual; there's an equally important benefit with something called "community immunity." The medical establishment can never achieve 100 percent vaccination rates—there will always be those who cannot get protected, either because they are too sick or have weakened immune systems and cannot respond to a vaccine (children with cancer on chemotherapy, for example), or because those children's parents refuse to vaccinate them. These children remain vulnerable to illness; yet if enough of the children in their community are immune, they won't be exposed to these germs as there aren't sick children to pass them along.

To achieve community immunity, over 95 percent of a community needs to be immunized. Thus, childhood vaccinations become more than just a way to keep one child healthy. They are part of a larger social obligation, performed by the healthy and willing for those less fortunate. Another important benefit in having a large portion of the community protected is the prevention of large-scale outbreaks. In 1994, infectious polio made its way to Canada in the form of a traveler from India. Yet because of Canada's high immunization rates, no large outbreak occurred.