Children dying of chickenpox has almost been eliminated since the introduction of a vaccine in 1995, U.S. researchers say. Dr. Mona Marin, John X. Zhang and Jane F. Seward of the Centers for Disease Control and Prevention in Atlanta say previous studies reported a 66 percent decline in chickenpox mortality rate during the first six years of the program. However, since then, vaccination coverage has increased substantially. The researchers updated the analysis of U.S. chickenpox mortality for 2002 to 2007 and assessed the impact of the first 12 years of the chickenpox. The study, published in the journal Pediatrics, found chickenpox deaths have dropped by 88 percent overall and by 97 percent for children and adolescents. In the last six years analyzed, a total of three deaths per age range were reported among children ages 1-4 and 5-9, compared with an annual average of 13 and 16 deaths, respectively, during the pre-vaccine years, the study says. \"The impressive decline in varicella [chickenpox] deaths can be directly attributed to successful implementation of the vaccination program,\" the researchers say in a statement.