Fig. 1
From: Asymptomatic transmission and the resurgence of Bordetella pertussis
Increase in B. pertussis incidence over time. Panel a shows B. pertussis cases in the United States from 1922 through 2012 and in the United Kingdom from 1940 through 2013 (from: [17] and [70]). Shaded regions correspond to the pre-vaccine era, the DTP era, and the DTaP era, respectively. Panels b and c show the incidence of B. pertussis by age group with darker color indicating younger ages in the US and UK, respectively. Infants less than 1 year old are labeled in darkest colors