title: An Outbreak of Varicella among children attending preschool and elementary school in Illinois.
abstract: In our investigation of a varicella outbreak among students in preschool, kindergarten, and grades 1-3 in Winnebago County, Illinois, we found an overall varicella vaccine efficacy of 88%, evidence that the circulating virus was a wild-type strain (as determined by polymerase chain reaction analysis), and evidence that vaccination of children </=15 months of age was associated with an increased risk for breakthrough varicella (relative risk, 3.7; 95% confidence interval, 1.1-13.1; P=.04). The efficacy of varicella vaccine might be improved if administration of the initial vaccine dose is delayed until children are >/=15 months of age.
authors.affiliation: Division of Infectious Diseases, Illinois Department of Public Health, Springfield, IL, USA. mdworkin@idph.state.il.us
authors.forename: Mark S
authors.initials: MS
authors.lastname: Dworkin
authors.forename: Charles E
authors.initials: CE
authors.lastname: Jennings
authors.forename: Jayne
authors.initials: J
authors.lastname: Roth-Thomas
authors.forename: Jo Ellen
authors.initials: JE
authors.lastname: Lang
authors.forename: Carol
authors.initials: C
authors.lastname: Stukenberg
authors.forename: John R
authors.initials: JR
authors.lastname: Lumpkin
mesh_terms: D002644:Chickenpox / Q000453:epidemiology* / Q000517:prevention & control; D019433:Chickenpox Vaccine / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D017714:Community-Acquired Infections / Q000453:epidemiology* / Q000517:prevention & control; D004196:Disease Outbreaks; D006801:Humans; D007087:Illinois / Q000453:epidemiology
chemical_list: D019433:Chickenpox Vaccine