Vaccines comprising an S. aureus alpha-toxin antigen and a pharmaceutically acceptable carrier are provided, and are useful for treating and preventing infections. The S. aureus alpha-toxin antigen may contain at least two alterations that reduce its toxicity and/or may be conjugated to or co-administered with another bacterial antigen. The vaccines may comprise one or more other bacterial antigens. Antibody compositions comprising antibodies to alpha-toxin and optionally one or more other bacterial antigens also are provided, and are useful for treating and preventing infections.