Attenuated Live Vaccine

**Semantic type:** Chemical Viewed Functionally

**Definition:** Any vaccine created by reducing the virulence of the infectious agent but still keeping the agent viable (live). In the production of an attenuated vaccine, the infectious agent is altered so that it becomes harmless or less virulent. This is in contrast to those vaccines produced by killing the pathogen (inactivated vaccine).

**Synonyms:** - LAV - Live Attenuated Vaccine