The active agent of a vaccine may be intact but inactivated or attenuated (with reduced). Vaccines are hailed as one of the most important public health achievements of the 20th century. New innovations in vaccine technology and new information about how the immune system works to protect us make this an exciting time in the field of vaccine research and development.
The first two have already been accomplished! While there is a concerted effort to end measles, the goal to achieve worldwide eradication of measles by 2010 has been interrupted by parents in Europe and parts of the United States choosing not to vaccinate their children leading to higher infection rates. To protect more children, scientists and doctors are working hard every day to develop new vaccines.