title: Over five-year follow-up of Oka/Merck varicella vaccine recipients in 465 infants and adolescents.
abstract: A total of 465 healthy infants and adolescents ages 12 months to 17 years without a known history of varicella or recent exposure to varicella-zoster virus VZV were immunized with live attenuated Oka/Merck varicella vaccine from November, 1984, through April, 1989. The vaccine administered was from 1 of 7 production lots containing from 950 to 3265 plaque-forming units and was well-tolerated with few side effects. The seroconversion rate for seronegative subjects was 94.6% (403 of 426). This varied by lot from 85% (950 plaque-forming units) to 100% (3010 and 3265 plaque-forming units). Breakthrough disease after exposure to varicella in seroconverters during 5 to 10 years of follow-up was 18.6% (75 of 403). The breakthrough disease was characterized by a maculopapular rash with a median of 35 lesions, most of which were macules. Breakthrough disease lasted a median of 5 days and the median temperature was 99 degrees F; 65.3% (49 of 75) of subjects were afebrile and 2.7% (2 of 75) of subjects had temperatures of > 102.9 degrees F. Varicella vaccine provides excellent (94.6%) seroconversion, and most children who developed breakthrough disease (18.6%) experienced a modified, milder form of illness than has been observed with natural varicella in unvaccinated subjects.
authors.affiliation: Duke Vaccine Unit, Duke University Medical Center, Durham, NC 27710, USA.
authors.forename: D A
authors.initials: DA
authors.lastname: Clements
authors.forename: C B
authors.initials: CB
authors.lastname: Armstrong
authors.forename: A M
authors.initials: AM
authors.lastname: Ursano
authors.forename: M M
authors.initials: MM
authors.lastname: Moggio
authors.forename: E B
authors.initials: EB
authors.lastname: Walter
authors.forename: C M
authors.initials: CM
authors.lastname: Wilfert
mesh_terms: D000293:Adolescent; D002644:Chickenpox / Q000453:epidemiology / Q000276:immunology / Q000517:prevention & control*; D019433:Chickenpox Vaccine; D002648:Child; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005500:Follow-Up Studies; D014645:Herpesvirus 3, Human / Q000276:immunology*; D006801:Humans; D007115:Immunization Schedule; D007223:Infant; D008297:Male; D011379:Prognosis; D012720:Severity of Illness Index; D013997:Time Factors; D014765:Viral Vaccines / Q000276:immunology / Q000627:therapeutic use*
chemical_list: D019433:Chickenpox Vaccine; D014765:Viral Vaccines