Patent ID: 7465443

Claim:
An immunogenic composition consisting essentially of an immunogenic vrg bacterial urea extract obtained from phase IV strains of at least one of B. pertussis, B. parapertussis, and B. bronchiseptica, wherein said extract comprises at least one expression product of vrg genes from said at least one of B. pertussis, B. parapertussis, and B. bronchiseptica, and wherein said extract is prepared by: a) culturing said at least one of B. pertussis, B. parapertussis, and B. bronchiseptica on blood medium to obtain isolated nonhemolytic colonies; b) inoculating cells of one or more colonies in liquid medium to give a suspension of cells; c) separating said cells from said liquid medium after culture; d) suspending the separated cells in a buffer comprising urea for at least an amount of time sufficient to form a bacterial lysate; and e) separating intact cells and insoluble material from soluble material, wherein said extract comprises said soluble material, and wherein the composition is immunogenic when administered to a subject.