Varicella Vaccine and Infection with Varicella–Zoster Virus

Varicella–zoster virus is the cause of both varicella (chickenpox) and herpes zoster (shingles). A live attenuated varicella vaccine was developed in Japan in 1974, and in 1995 it was approved for use in the United States. The policy of universal vaccination of susceptible children and adults has had a profound effect on the epidemiology of varicella. Its effect on the epidemiology of zoster remains to be seen, in part because of the long delay between primary infection with varicella–zoster virus and the subsequent occurrence of zoster.Before varicella vaccine was introduced, chickenpox developed in approximately 4 million persons, most of . . .