Reduced risk of pertussis among persons ever vaccinated with whole-cell pertussis vaccine compared to recipients of acellular pertussis vaccines may have been confounded by age

摘要

The phasing out of whole-cell pertussis (wP)-containing vaccines in an integrated healthcare system with complete electronic records and a centralized laboratory has provided Witt et al with a unique opportunity to compare its effectiveness against pertussis infection to the newly introduced acellular pertussis (aP)-containing vaccines [1]. This retrospective study compared a large cohort of subjects vaccinated with at least 1 dose of wP with subjects vaccinated only with aP, and found considerable protection from clinical pertussis associated with wP. However this association may have been confounded by age, and therefore further analysis of the data is required before conclusions can be drawn.