A vaccination is the injection of a killed or weakened organism to boost the immune system’s ability to fight against that organism. Vaccination is a suspension of attenuated or killed microorganisms that are administered for prevention or treatment of infectious disease. The vaccination helps the immune system to recognize and fight specific germs. Perfect immunity against a disease is not guaranteed through vaccination. Immunization refers to making someone immune against infections or diseases. Immunization is not only caused by Vaccines but there are also some diseases that cause immunization after an individual encounters and recovers from that disease.