Varicella-Zoster Virus Vaccine

Varicella-zoster virus (VZV) vaccine (VARIVAX; Merck Research Laboratories [MRL], Merck & Co. Inc., West Point, PA) was licensed in the United States in 1995, after 14 years of clinical research in this country. Following licensure, VARIVAX was recommended by the American Academy of Pediatrics [1] and the Advisory Committee for Immunization Practices [2] for universal use in children 12 months to 12 years of age and in susceptible adolescent and adult populations. The VZV vaccine has been approved for use in certain immunosuppressed populations in several countries of the Far East and in Europe for > 10 years. It has generally taken longer (Japan, Korea, Germany, Hong Kong, Singapore, the Philippines, and Indonesia) for acceptance as a pediatric vaccine, but several other countries have recommended its use in healthy children, adolescents, and adults. This article summarizes the pathogenesis of VZV infection, the epidemiology of the diseases caused by VZV (chickenpox and herpes zoster [HZ]), the immune response to natural infections vs. to immunization, treatment of VZV infections, the development of the attenuated vaccine strain and related clinical trials, and future directions of vaccine-related research.