Vaccines, Infectious Diseases, and Immunity in Children

Vaccination is a medical procedure that produces immunity to a disease in an individual by deliberately exposing the person to a less harmful (weakened or dead) version of a pathogen, such as the virus that causes measles. This exposure stimulates the immune system to create antibodies, which offer protection against future exposures to the same pathogen. In some cases, vaccination uses a closely related pathogen that produces a less serious disease but confers immunity to a more serious disease: For instance, Edward Jenner demonstrated in the late 17th century that vaccination with cowpox conferred immunity to smallpox. The term vaccination was coined by Jenner to describe this process, using the Latin word for cow (vacca), but today the terms vaccination and immunization are used interchangeably ...