In this issue of Pediatrics Acosta et al1 present a tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis, adsorbed (Tdap) vaccine effectiveness study in adolescents in Washington State during the first 6 months of 2012. Their findings support the previous Tdap effectiveness data from Wisconsin.2 The duration of Tdap effectiveness is disappointing, particularly because case-control studies tend to inflate efficacy.3
In 4 recent publications (including 1 article in Pediatrics) I have discussed epidemic pertussis and why vaccines fail.4–7 Before discussing why Tdap vaccine effectiveness wanes so rapidly, it seems worthwhile to discuss how rapidly protection wanes after a natural infection in the pre-Tdap era and to take a realistic look at the resurgence of pertussis.
The resurgence of pertussis is often attributed to the switch from whole-cell pertussis vaccines to acellular products. However, the increase in reported pertussis began ∼14 years before the...