Vaccination is the administration of a vaccine to help the immune system develop protection from a disease. Vaccines contain a microorganism or virus in a weakened, live or killed state, or proteins or toxins from the organism. Vaccination is one of the most effective ways to prevent diseases. Babies are born with protection against some diseases because their mothers pass antibodies (proteins made by the body to fight disease) to them before birth. Vaccinations can help protect your child from serious diseases caused by germs. The story of vaccines did not begin with the first vaccine–Edward Jenner's use of material from cowpox pustules to provide protection against smallpox. Inactivated vaccines; Subunit, recombinant, polysaccharide, and conjugate vaccines; Toxoid vaccines. Live-attenuated vaccines. and these days DNA vaccins have also come into play. Between 1890 and 1950, bacterial vaccine development proliferated, including the Bacillis-Calmette-Guerin (BCG) vaccination, which is still in use today, in Asian countries countries specifically. A vaccine is a type of medicine that trains the body's immune system so that it can fight a disease. Vaccines are the most effective way to prevent infectious diseases. This page explains how vaccines work, what they contain and the most common side effects.