Attenuated Live Virus Vaccine

**Semantic type:** Chemical Viewed Functionally

**Definition:** Live vaccines prepared from microorganisms which have undergone physical adaptation (e.g., by radiation or temperature conditioning) or serial passage in laboratory animal hosts or infected tissue/cell cultures, in order to produce avirulent mutant strains capable of inducing protective immunity. Live-attenuated vaccines are used when a CD8+ T Cell (cellular cytotoxicity) response is desired.

**Synonyms:** - Live Attenuated Viral Vaccine