Decline in annual incidence of varicella--selected states, 1990-2001.

Varicella (chickenpox) is a common, highly infectious, and vaccine-preventable disease. Before the introduction of the live attenuated varicella vaccine in 1995, approximately 4 million cases of varicella occurred annually in the United States, resulting in approximately 11,000 hospitalizations and 100 deaths. In 1996, the Advisory Committee on Immunization Practices (ACIP) recommended routine vaccination of all children at age 12-18 months, catch-up vaccination of all susceptible children before age 13 years, and vaccination of susceptible persons with close contact to persons at high risk for serious complications. In 1999, ACIP updated these recommendations to include vaccination requirements for child care and school entry and for postexposure; ACIP also strengthened recommendations for vaccination of susceptible adults and indicated that varicella vaccine should be considered for outbreak control. Changes in the national annual reported incidence of varicella disease during 1972-1997 have been reported previously. This report summarizes trends in the annual reported incidence of varicella disease in selected states during 1990-2001. The findings underscore the continued need to improve varicella surveillance to monitor the impact of the varicella vaccination program and assess any changes in varicella transmission and disease.