Isolation from Bordetella pertussis of Protective Antigen free from Toxic Activity and Histamine Sensitizing Factor

Abstract

IN view of the untoward reactions which pertussis vaccine occasionally produces in vaccinated children, the importance is now generally recognized of developing a vaccine with protective properties yet free from those factors responsible for reactions. van Hemert, van Wezel and Cohen¹ described a method of extracting the protective antigen from Bordetella pertussis by treating a suspension of the organisms with Na-deoxycholate and then with DNase and RNase. This treatment was followed by gel-filtration to remove the Na-deoxycholate together with other low molecular weight compounds. The resulting extract, SDE, contained the protective antigen but also toxic factors. Further experiments have now been made, which are reported below, to obtain the protective antigen free from toxic factors.