Brand-specific rates of pertussis disease among Wisconsin children given 1–4 doses of pertussis Vaccine, 2010–2014. Issue 45 (21st October 2020)

• Record Type: Journal Article
• Authors: Conway, James H.; Davis, Jeffrey P.; Eickhoff, Jens C.; Pool, Vitali; Greenberg, David P.; Decker, Michael D.
• Is Part Of: Vaccine. Volume 38:Issue 45(2020)
• Page Start: 7063
• Page End: 7069
• Publication Date: 2020-10-21
• Subjects: Pertussis vaccine -- Vaccines -- Acellular -- Effectiveness -- Case-cohort study; Vaccines -- Periodicals; 615.372
• DOI: 10.1016/j.vaccine.2020.09.016
• Languages: English
• ISSNs: 0264-410X

Abstract

Highlights: Available pertussis vaccines performed similarly among young children in Wisconsin. Risk of pertussis was substantially higher among those whose vaccinations were delayed. Sample survey methodology can provide cohort data for a case-cohort study design. Abstract: Background: Acellular pertussis vaccines were initially licensed based on placebo-controlled efficacy trials, but such trials are no longer ethical. The effectiveness of current pertussis vaccines among properly vaccinated children <5 years is so high that a randomized trial is infeasible. Fluctuations in pertussis incidence and characteristics of the US vaccine marketplace make selection of suitable controls for a case-control study problematic. To satisfy an FDA requirement to evaluate rates of pertussis following licensure of Pentacel® vaccine, we used a case-cohort study design with a novel method for characterizing the cohort population. Methods: This prospective, observational study was conducted in Wisconsin from 2010 to 2014 among Wisconsin residents <60 months of age who received ≤four doses of pertussis vaccine (surveillance population). Cases were identified by the Wisconsin Division of Public Health. Characteristics and pertussis vaccinations of the surveillance population were estimated by ongoing random telephonic survey. The primary objective was to determine rates of pertussis disease among those who received only Pentacel vaccine (Group 1) vs those who received a single brand of vaccine other than Pentacel vaccine (Group 2). Results: 1195 pertussis cases were identified. It was estimated that the surveillance population accrued a total of 1, 133, 403 person-years (Group 1, 39%; Group 2, 41%; Group 3 [those not in Group 1 or Group 2], 20%). Pertussis rates were similar in Group 1 (98.9/100, 000) and Group 2 (96.2/100, 000); rate ratios were 1.03 (unadjusted; 90% CI, 0.92–1.15) and 0.99 (adjusted; 90% CI, 0.89–1.12). Persons with one or more delayed vaccinations had a 66% higher risk of pertussis (90% CI, 39–96%). Discussion: Pertussis protection was not found to differ for recipients of the newly licensed vs other available pertussis vaccines. Delayed vaccination substantially increased risk of pertussis. Sample survey methodology was able to characterize the study cohort and enable an otherwise-infeasible study. Clinical Trial Registry number: ClinicalTrials.gov, NCT01129362.