Varicella vaccination

Letter to the Editor Editor, – Before the universal varicella vaccination program, 95% of adults in the USA experienced natural chickenpox (usually as school-aged children). .4 A recent study found a 90% overall increase in adult shingles, from 2.77/1000 to 5.25/1000, during a period of increasing varicella vaccine coverage, 1998-2003.5 If the outcomes in this and other UK studies are due to an immunologically-mediated link (that is, low varicella incidence produces an increase in the incidence of herpes zoster), then the approximate 50% reduction in risk of herpes zoster achieved in a large trial of a zoster virus vaccine, at best reduces shingles incidence back to the prelicensure rate. The incidence of varicella and herpes zoster in Massachusetts as measured by the Behavioral Risk Factor Surveillance System (BRFSS) during a period of increasing varicella vaccine coverage, 1998-2003.