Preparation of cholera vaccines by fluorocarbon extraction of cholera Vibrio suspensions.

Experimental cholera vaccines were prepared from suspensions of cholera vibrios which were extracted with Genetron-113. These vaccines, when compared with a control preparation which was not treated with Genetron, had a lower nitrogen content and were less toxic for mice but were as effective in protecting mice against infection and in inducing agglutinating and vibriocidal antibody responses in rabbits. This procedure may permit the preparation of cholera vaccines with a higher antigenic content without the corresponding increase in toxic reactions.