Question

Short definition of vaccine

Answer 1

an antigenic substance prepared from the causative agent of a disease or a synthetic substitute, used to provide immunity against one or several diseases....

Answer 2

a vaccine is a preparation of killed weakened disease causing microbes.when a vaccine is injected into a body of healthy person his/her body produces antibodies against these killed of weaken microbes.thees antibodies  remain in the body and protect us from future infection by the same microbes.thus a vaccine help in preventing disease caused by microbes(eg, cholera,typhoid,smallpox and hepatitis)