ELISA detection of rSpaA, rSpaB, rSpaC664, rSpaC427, and rSpaC253 antibody titers in sera of mice vaccinated with rSpaC664, rSpaC427, or rSpaC253 and of the nonimmunized control mice. Mice were immunized and boosted 3 weeks apart with 40 μg of rSpas. Serum samples were collected at 14 days after boosting. Antibody titers are expressed as the average titer ± the standard deviation of the average of 10 mice each.