The Occurrence Ofbordetella Pertussisserotypes in Australia, 1950–1970

The results are reported of a serotyping survey of 252 field strains and 33 vaccine strains of Bordetella pertussis isolated in Australian hospitals between 1950 and 1970. Strains isolated before 1960 were predominantly of serotype 1, 2; most subsequent strains were of serotype 1, 3, but a large minority of serotype 1, 2, 3 was Isolated from late 1967 onwards. Vaccines were generally low in type-specific antigen “3” during the period 1958–1961 and in antigen “2” during the period 1962–1963. Some evidence is presented tending to support the theory that type-specific immunity plays an important role in human pertussis prevention.