Pitfalls in the Preparation of Monotypic Agglutinating Antisera for Bordetella Pertussis

Summary Agglutination tests showed that 5 cultures of Bordetella pertussis, strain no. 18/323, which are used in Britain to assess the protective value of whooping-cough vaccine by mouse-protection tests, are not serologically identical. “ Monotypic ” antisera used for the typing of Bord. pertussis by slide-agglutination were found not to be serologically “ pure ”. A number of sera supposed to contain antibodies for factor 1 only proved to contain antibodies for a variety of other antigens, including factors 2 and 3. Several cultures in which only factor 1 was detected by slide agglutination were used as vaccines in rabbits. The resulting antisera contained other antibodies, and in some cases large amounts of antibody for factor 2 were detected. Individual rabbits varied considerably in the relative amounts of agglutinin for factors 1, 2 and 3 produced as a result of vaccination with the same bacterial suspension. The implications of these findings were examined in relation to the claim that immunity to whooping-cough is influenced by the serological type of the vaccine strain of Bord. pertussis.