A live vaccine is a type of vaccine that contains a weakened or modified form of the pathogen that causes the disease. This stimulates an immune response within the individual's body, leading to the development of immunity to the disease. There are various synonyms for live vaccine including attenuated vaccine, weakened vaccine, and modified live vaccine. These vaccines are often preferred over inactivated vaccines as they provide long-lasting immunity with a single dose, and are generally more effective against viral diseases. However, they may pose a risk to individuals with weakened immune systems and a careful risk assessment should be conducted before administering them.