Antigenic divergence between Bordetella pertussis clinical isolates from Moscow, Russia, and vaccine strains.

We analyzed temporal changes in the frequencies of the ptxA, prn, fim2, and fim3 alleles in Bordetella pertussis strains isolated from pertussis patients in Moscow, Russia, from 1948 to 2004. The three strains used for the whole-cell vaccine harbored the alleles ptxA2, ptxA4, prn1, fim2-1, and fim3A. Vaccine-type alleles of ptxA (ptxA2 and ptxA4) were characteristic for all prevaccination strains and for 96% of the strains isolated in the 1960s and 1970s.