Efficacy in infancy of oligosaccharide conjugate Haemophilus influenzae type b (HbOC) vaccine in a United States population of 61,080 children. The Northern California Kaiser Permanente Vaccine Study Center Pediatrics Group.
The efficacy of the HbOC conjugate Haemophilus influenzae type b vaccine was evaluated in a study population of 61,080 infants in the Northern California Kaiser Permanente Medical Care Program. Between February, 1988, and June, 1990, the HbOC vaccine was given as part of a three-dose series at 2, 4, and 6 months of age to 20,800 infants. The study population included children with a well-care visit at a study center during the first 6 months of life. There were 25 cases of Haemophilus influenzae type b disease in the study population: 22 in unvaccinated children and 3 in children who received only one dose of HbOC vaccine. The efficacy of the full three-dose series was evaluated by several methods: a primary analysis comparing fully vaccinated children with unvaccinated children from 7 to 18 months of age; a stratified exact analysis adjusted for age and seasonality; and a case-control analysis which further adjusted for known risk factors. The efficacy of three doses of vaccine was 100% with the lower bound of the 95% confidence interval for the three analyses at 68, 71, and 64%, respectively. There were no cases of disease resulting from two doses of HbOC vaccine yielding an estimate of 100% efficacy (95% confidence interval, 47 to 100) for two doses of HbOC vaccine. However, for children who had received only one dose of HbOC vaccine, vaccine efficacy was estimated to be 26% and the possibility that one dose of HbOC vaccine had no efficacy could not be excluded.(ABSTRACT TRUNCATED AT 250 WORDS)
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Kaiser Permanente Medical Center, Oakland, CA 94611.
Shinefield
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Fireman
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Hiatt
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Polen
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Vittinghoff
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D001426:Bacterial Proteins; D001428:Bacterial Vaccines; D015982:Bias; D002140:California; D016022:Case-Control Studies; D015331:Cohort Studies; D016001:Confidence Intervals; D006192:Haemophilus Infections / Q000517:prevention & control*; D018073:Haemophilus Vaccines; D006193:Haemophilus influenzae / Q000276:immunology*; D006801:Humans; D007115:Immunization Schedule; D007223:Infant; D012107:Research Design; D014611:Vaccination; D014614:Vaccines, Synthetic
D001426:Bacterial Proteins; D001428:Bacterial Vaccines; D018073:Haemophilus Vaccines; D014614:Vaccines, Synthetic; C061963:HibTITER protein, Haemophilus influenzae