Vaccines

Vaccines are major public health tools that are responsible for the eradication of smallpox, the prevention of childhood diseases, and the control of many injurious illnesses. Treatment with a vaccine results in the development of antibodies specific for some target, known as an antigen. The antigen can be a virus, for example, but it is really a protein that is part of the virus. When the antibody binds to the protein on the virus, the virus is prevented from infecting the cells of the vaccinated host. Antibody molecules are Y-shaped proteins that bind to the antigen at the tip of the two arms of the Y. The binding is highly specific for the antigen in the vaccine, and the antibody can be thought of as a specific deactivator or blocker. A....