Corresponding Author: Pejman Rohani; Rohani@uga.edu
After implementing routine vaccination in the 1940s, the United States witnessed a 100-fold reduction in pertussis cases, also known as whooping cough, leaving most to believe the disease to be essentially eliminated. However, this respiratory disease has made a surprising comeback, with a startling 48,277 reported cases in 2012, the lastest peak year. Since 2010, the CDC has also noted an increase in reported cases among 7 through 10 year old children, as well as teens. Public health officials and researchers, in an effort to pinpoint the underlying cause of this recent re-emergence, have shifted their focus towards assessing vaccine effectiveness. In this recently published research article, CEID member Pej Rohani and colleagues created transmission models containing contrasting “vaccine failure” hypotheses and fitted these to 16 years of data provided by the Massachusetts Department of Public Health (MDPH). Specifically, they examined three potential areas of failure including (1) the vaccine fails to protect some fraction of individuals, (2) waning in vaccine-induced protection over time, and (3) failure in the degree of protection. Their model also includes age-specific immunization and demographic data, age-specific contact network information, and age-specific reporting efficiencies. Their model indicates that the reemergence of pertussis is the result of incomplete historical coverage with a vaccine that presents slowly waning immunity, and that school children are the core transmission group. Overall, their study suggests that targeting school children, rather than adults, is more likely to reduce transmission across the US, and that routine vaccination is crucial to facilitate its elimination from the population at large.
Cellès, Matthieu Domenech De, et al. “The Impact of Past Vaccination Coverage and Immunity on Pertussis Resurgence.” Science Translational Medicine, vol. 10, no. 434, 2018, doi:10.1126/scitranslmed.aaj1748.