Vaccines work by preparing the body to fight germs that may cause illness. When germs or disease-causing micro-organisms enter the body, the immune system produces antibodies to fight them. Vaccines contain antigens, which are dead or considerably weakened organisms or part of the organism that when administered, help to produce antibodies. Whenever a vaccinated individual is exposed to the actual disease, the antibodies already produced destroy and eliminate the germs and prevent the individual from ill-health and/or death. Vaccines provide immunity from various kinds of infectious diseases.