Despite decades of high vaccination coverage, pertussis has remained endemic and reemerged as a public health problem in many countries in the past 2 decades. Waning of vaccine-induced immunity has been cited as one of the reasons for the observed epidemiologic trend. A review of the published data on duration of immunity reveals estimates that infection-acquired immunity against pertussis disease wanes after 4–20 years and protective immunity after vaccination wanes after 4–12 years. Further research into the rate of waning of vaccine-acquired immunity will help determine the optimal timing and frequency of booster immunizations and their role in pertussis control.
From the *Department of Epidemiology, University of North Carolina-Chapel Hill, Chapel Hill, NC; †Director of the National Cancer Centre for Epidemiology at the Italian National Institute of Health and the Laboratories of Epidemiology and Biostatistics, Istituto Superiore di Sanità, Rome, Italy; and the ‡Department of Pediatrics, Children's Hospital and Regional Medical Center, University of Washington, Seattle, WA
Address for correspondence: Aaron M. Wendelboe, Department of Epidemiology, McGavran-Greenberg Hall, University of North Carolina, CB# 7435, Chapel Hill, NC 27599-7435. E-mail email@example.com.