Definition

A sterile, lyophilized preparation of the Oka/Merck strain of the live, attenuated varicella zoster virus (VZV), that can be used to prevent varicella, commonly known as chickenpox, or herpes zoster (HZ), commonly known as shingles. Upon reconstitution and subcutaneous vaccination with the VZV strain Oka/Merck live antigen, this vaccine induces antigen-specific T-cell and B-cell immune responses against the VZV, thereby protecting against VZV infection.