Comparison of the protective effects of the pertussis acellular vaccine with the component vaccine, which have different amounts of fimbriae, against the experimental aerosol infection of mice with Bordetella pertussis.

We obtained highly purified fimbrae from Bordetella pertussis cells which gave a single band in SDS-polyacrylamide gel electrophoresis. Using the purified fimbriae, we prepared anti-fimbriae rabbit or goat IgGs by fimbriae-Sepharose affinity chromatography, and developed ELISA for its determination. The concentration of fimbriae in our former type of acellular vaccine (80 micrograms per ml) was determined to be 20 ng per ml, and that in our component vaccine was at an almost negligible level. To estimate the protective effects of the small levels of fimbriae, we evaluated the protective activities of three types of vaccines; the former type acellular vaccine (pertussis toxin (PT): filamentous hemagglutinin (FHA): fimbriae = 15:61:0.02 (microgram per ml)), the two-component vaccine (16:64:0.0001), and the three-component vaccine (16:63:0.8). The three types of vaccines showed no significant differences in protectivity against the experimental aerosol infection suggesting that these levels of fimbriae are not effective against the experimental aerosol infection of mice with Bordetella pertussis.