The purpose of this cohort study is to determine vaccine-specific rates of pertussis disease during the period of the study, among Wisconsin residents younger than 60 months of age (the Surveillance Population), and to descriptively compare the proportion of such persons vaccinated with Pentacel® vaccine who acquire pertussis disease to the proportion of such persons vaccinated with any other Diphtheria and Tetanus Toxoids and Acellular Pertussis (DTaP) vaccine who acquire pertussis disease.

Primary Objective:

To determine the rates and relative risk of pertussis disease among Surveillance Population members who have received Pentacel vaccine or another pertussis vaccine.

The study will be conducted by the University of Wisconsin School of Medicine and Public Health, in collaboration with the Wisconsin Division of Public Health (WDPH).

Epidemiological and laboratory surveillance for pertussis disease among Wisconsin residents is routinely conducted by the WDPH. During the period of the study, de-identified data regarding all incident pertussis cases will be obtained from WDPH and vaccination coverage rates, by vaccine regimen, age group, and period of time, will be obtained from ongoing marketplace surveillance conducted on behalf of the Sponsor by a national sample-survey organization. Using these data, rates of pertussis disease will be determined.

No vaccine will be administered as part of this study.

Inclusion Criteria :

• Persons will be under surveillance for this study whenever the following three conditions are true: the individual resides in Wisconsin, is age birth through 59 months, and is within the surveillance period of 01 October 2009 through 30 September 2014 (or as extended in order to accrue 61,761 person years of Pentacel vaccine exposure).

Exclusion Criteria :

• Not applicable

Wisconsin residents younger than 60 months of age.

Qualified researchers may request access to patient level data and related study documents including the clinical study report, study protocol with any amendments, blank case report form, statistical analysis plan, and dataset specifications. Patient level data will be anonymized and study documents will be redacted to protect the privacy of trial participants. Further details on Sanofi's data sharing criteria, eligible studies, and process for requesting access can be found at: https://vivli.org