The highest incidence of pertussis, 62.5 per 100,000 cases, was in children <6 months of age; children 6-11 months of age had an incidence of 33.2 per 100,000 cases, in 2019 (provisional data).2
Note: Cases include individuals who range <6 months of age to 20 years of age and older, including unknown ages. Surveillance data have limitations and are often incomplete: about one-half of pertussis cases in 2018 among children 6 months to 6 years of age had unknown pertussis vaccination history. These data cannot be used to interpret vaccine effectiveness or to assess risk, as the data are incomplete and there is no healthy comparison group.
DTaP=diphtheria, tetanus, and acellular pertussis.
References: 1. Pertussis. In: Hamborsky J, Kroger A, Wolfe C, eds. Epidemiology and Prevention of Vaccine Preventable Diseases. 13th ed. Washington, DC: Public Health Foundation; 2015:216-278. 2. Centers for Disease Control and Prevention. 2019 Provisional pertussis surveillance report. https://www.cdc.gov/pertussis/downloads/pertuss-surv-report-2019-508.pdf. Updated February 2020. Accessed April 9, 2021.