Patent ID: 7105317

Claim:
A method of producing a composition comprising an 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 a liquid medium with cells of one or more of said isolated nonhemolytic colonies to give a suspension of cells; c) separating said cells in said suspension of 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 in the bacterial lysate to form the extract comprising the soluble material, including said at least one expression product of vrg genes from said at least one of B. pertussis, B. parapertussis , and B. bronchiseptica.