A live attenuated varicella-zoster (V-Z) virus vaccine has been developed and tested by Dr. M. Takahashi and his colleagues in Japan. This vaccine appears to prevent varicella and is associated with minimal side effects even in patients at high risk to develop severe varicella. Antibody to V-Z virus appears after V-Z vaccination. This antibody has been detected by a variety of serologic technics, and it has been demonstrated to persist for as long as two years after vaccination. Thus far, V-Z vaccine has not been associated with subsequent zoster, but long-term studies will be required before this possibility can be ruled out.