Vaccination

Vaccinations are used to prevent infectious diseases. A weakened form of the infectious pathogen is used to stimulate the body's immune system to manufacture antibodies enabling the body to defend itself against the infectious pathogen. Vaccinations work because the immune system in the bodies of animals, birds, or humans is able to utilize the immunogen that is introduced to make antibodies. The antibodies destroy or neutralize the infectious agent whether it is a virus, bacteria, fungi, or some other pathogen. There are four types of vaccines. Those that contain bacteria or viruses that have been altered are called live attenuated vaccines. Vaccines that contain only parts of the infectious bacteria or virus are component vaccines. Killed vaccines use bacteria or viruses that have been killed. ...