M Jamal Saadh, H Mousa Sbaih,
Abstract
A vaccine is an antigenic substance prepared from the causative agent of a disease, used to provide immunity to a particular disease. The vaccine is often made from attenuated or killed forms of the microbe. The agent stimulates the body's immune system to recognize the agent as foreign, destroy it, and "remember" it, so that the immune system can more easily recognize and destroy any of these microorganisms that it later encounters. We reviewed the recent literature on types of vaccines and older studies were included selectively if historically relevant. Attenuated and killed vaccine have been studied extensively to help eradication the infectious disease development, and thereby decrease the need for drugs.