Effect of Vaccination on Bordetella pertussis Strains, China

摘要

Whole-cell pertussis vaccine was introduced in China in the early 1960s. We used standard typing methods to com-pare 96 Bordetella pertussis isolates collected before and after introduction of vaccination, during 1953–2005. The fol-lowing vaccine-type alleles of the pertussis toxin (ptx) gene were characteristic for all prevaccination strains: ptxA2, ptxA3, and ptxA4. The shift to ptxA1 occurred since 1963. All isolates collected since 1983 contained ptxA1. Pertactin (prn) allele 1, prn1, was predominant, although prn2 and prn3 have been detected since 2000. Serotypes fi mbriae (Fim) 2 and Fim2,3 were found in all isolates collected be-fore 1986. During 1997–2005, Fim3 became prevalent. Al-though changes in electrophoresis profi les over time were observed, the predominant profi les during 1997–2005 re-sembled those during the prevaccine era and those found in Europe before the 1990s. B. pertussis strains in China may differ from those in countries that have a long history of high vaccine coverage