First documented vaccines began when a British doctor Edward Jenner noticed milkmaids who had cowpox never contracted small pox. He then carried out an experiment in 1796 in which puss from a cowpox blister was inserted into an eight year old boy and proved that having been inoculated with cowpox the boy was immune to smallpox. From this beginning vaccines have been developed to protect against many fatal or serious diseases. Better yet, smallpox has been eradicated thanks to the pioneering work of Edward Jenner.
Today immunization starts at birth and most are usually completed by the time the child is two years old. Why start so early? Why not wait until the child is grown? This is what the U.S. Centers for Disease Control and Prevention (CDC) has to say.
- Newborn babies are immune to many diseases because they have antibodies they got from their mothers. However, this immunity goes away during the first year of life. Also, young children do not have this "maternal immunity" against some diseases, such as whooping cough.
- If an unvaccinated child is exposed to a disease germ, the child's body may not be strong enough to fight the disease. Before vaccines, many children died from diseases which vaccines now prevent, such as whooping cough, measles, and polio. Those same germs exist today, but because babies are now protected by vaccines, we do not see these diseases nearly as often.
- Immunizing individual children also helps to protect the health of our community, especially those people who cannot be immunized. These include children who are too young to be vaccinated (for example, children less than a year old cannot receive the measles vaccine but can be infected by the measles virus), those who cannot be vaccinated for medical reasons (for example, children with leukemia), and those who cannot make an adequate response to vaccination.