Vaccine efficacy was similar to that reported in other settings.
Pertussis has been on the rise since early in the decade, including among vaccinated children. Concurrently, there has been a sharp increase in the proportion of Bordetella pertussis strains lacking pertactin, a component of acellular pertussis vaccines. To evaluate whether this bacterial genetic change might contribute to the rise in pertussis by reducing the efficacy of acellular pertussis vaccines, researchers conducted two case-control studies in Vermont.
The researchers analyzed health records to assess the efficacy of diphtheria toxoid, tetanus toxoid, and acellular pertussis (DTaP) vaccine among children aged 4 to 10 years, and the efficacy of tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine among thos…