Mice vaccinated with a combination of two Staphylococcus aureus antigens consisting of a recombinant collagen-binding protein (CnBP) and alpha-toxoid (α-toxoid) were significantly protected from intramammary challenge infection with S. aureus. The average number of bacteria recovered from the glands of mice vaccinated with the combination of CnBP/α-toxoid was significantly lower compared to the average number of bacteria recovered from the glands of mice vaccinated with only CnBP or α-toxoid or controls (P≤0.01). Histopathological examination of mammary glands of mice vaccinated with CnBP together with α-toxoid showed no pathological changes, whereas glands of mice vaccinated with CnBP or α-toxoid alone developed severe mastitis and showed both focal and disseminated necrosis.