Theoretical, practical and statistical basis for a general control method of activity for anti-Brucella vaccines

Lots of five weeks old female CD-1 mice were vaccinated at several doses with living (B. abortus 19), killed whole cells or purified fractions vaccines. The doses were the number of bacterial cells injected per mouse, either viable (living vaccines), total (killed) or number calculated from the yield of extraction. The mice were intraperitoneally injected with a lyophilized standard challenge, 2 X 10(5) Brucella abortus 544, thirty days after vaccination. In two assays, B. melitensis H.38 was used as challenge at several doses. Responses to a good live vaccine were dose independent. Responses to killed whole cell and purified fractions were usually dose dependent. A reference lyophilized vaccine previously prepared and titrated would give the reference response to one unit. These data can be used to devise a general control method of activity for anti-Brucella vaccines. This was proposed and discussed in the preceding paper.