Improved survival of BALB/c and ICR mice immunized with IsdB and challenged with S. aureus Becker. (A, B, and C) Survival curves for three independent experiments performed with 20 to 30 BALB/c mice per group. (D, E, and F) Survival curves for three independent experiments performed with 10 to 20 ICR mice. •, survival of mice immunized with IsdB-APA; ○, survival of mice immunized with AAHSA.