A live virus vaccine is a type of vaccination that uses live viruses to stimulate the body's immune system to fight off viruses. However, there are several synonyms for this type of vaccine, including "attenuated vaccine," "replicating vaccine," or "viral vector vaccine." An attenuated vaccine uses a weakened form of the virus to stimulate the immune system. Replicating vaccines replicate the virus in the body to mimic an actual viral infection, and viral vector vaccines use a virus to deliver specific proteins to cells in the body to create an immune response. These synonyms all refer to vaccines that are designed to mimic natural viral infections, helping the body develop immunity against the real virus.