Diane Kruse, age 8, of Concord, N.H., for her question:

WHO GAVE THE FIRST VACCINATION?

A'vaccination is the introduction of weakened or dead viruses or bacteria or their poisons into the body to develop resistance to disease. Edward Jenner introduced the vaccination as a preventitive measure against smallpox in 1796. Jenner was an English doctor.

Material introduced into the body with a vaccination is called a vaccine. Vaccines must be strong enough to cause the body to develop resistance but weak enough so they will not infect the body or cause serious illness.

Effective vaccines have been developed against cholera, diphtheria, German measles, influenza, measles, rabies, Rocky Mountain Spotted Fever, smallpox lockjaw, typhoid and parathyphoid, typhus and yellow fever.

Most vaccines are injected into the body although the Sabin polo vaccine is taken by mouth. Vaccination comes from the Latin word vacca, meaning cow. The term originally referred to the injection of cowpox virus to prevent smallpox.