title: Clinical survey of natural varicella compared with breakthrough varicella after immunization with live attenuated Oka/Merck varicella vaccine.
abstract: OBJECTIVE
  To prospectively characterize varicella occurring in children previously immunized with a live attenuated varicella vaccine (breakthrough varicella) through daily observation by medical personnel and to compare it with natural varicella followed in the same manner.
  
  
  METHODS
  A blinded clinical survey.
  
  
  METHODS
  Four pediatric practices (two private; two hospital-based).
  
  
  METHODS
  Healthy 12-month-old through 17-year-old children with chickenpox were studied; 92 had natural varicella and 58 had breakthrough varicella. SELECTION PROCEDURES AND INTERVENTIONS: Study personnel, unaware of vaccination status, documented the clinical characteristics of each patient in the office or at the patient's home each day from enrollment until the day after the total number of lesions increased less than 10%. A standard form documenting number and description of lesions, temperature, duration of illness, and associated clinical complaints was completed each day by the same study personnel. Acute and convalescent sera were obtained on breakthrough cases.
  
  
  RESULTS
  Antibody to varicella-zoster virus was measured by the glycoprotein-based enzyme-linked immunosorbent assay. Of those with sera available, 85% were serologically confirmed. Eighty-seven percent of enrollees had a known exposure to chickenpox, with at least two thirds of each group having a greater than 4-hour or a household exposure. The numbers of total and vesicular lesions were significantly higher in the natural varicella group, regardless of exposure status (P = .021 to < .001). The group with breakthrough varicella had a significantly lower incidence of fever (P < .001) and a significantly shorter duration of illness (P < .001). Other associated constitutional complaints and complications were not significantly different between groups.
  
  
  CONCLUSIONS
  Varicella in vaccine recipients is clinically modified and significantly less severe than natural disease.
authors.affiliation: Temple University School of Medicine, Philadelphia, PA.
authors.forename: H H
authors.initials: HH
authors.lastname: Bernstein
authors.forename: E P
authors.initials: EP
authors.lastname: Rothstein
authors.forename: B M
authors.initials: BM
authors.lastname: Watson
authors.forename: K S
authors.initials: KS
authors.lastname: Reisinger
authors.forename: M M
authors.initials: MM
authors.lastname: Blatter
authors.forename: C O
authors.initials: CO
authors.lastname: Wellman
authors.forename: S A
authors.initials: SA
authors.lastname: Chartrand
authors.forename: I
authors.initials: I
authors.lastname: Cho
authors.forename: A
authors.initials: A
authors.lastname: Ngai
authors.forename: C J
authors.initials: CJ
authors.lastname: White
mesh_terms: D000293:Adolescent; D002644:Chickenpox / Q000276:immunology / Q000473:pathology / Q000503:physiopathology*; D019433:Chickenpox Vaccine; D002648:Child; D002675:Child, Preschool; D014645:Herpesvirus 3, Human / Q000276:immunology*; D006801:Humans; D007114:Immunization; D007223:Infant; D011446:Prospective Studies; D014613:Vaccines, Attenuated / Q000276:immunology; D014765:Viral Vaccines / Q000276:immunology*
chemical_list: D019433:Chickenpox Vaccine; D014613:Vaccines, Attenuated; D014765:Viral Vaccines