Hemolysin A has been shown to play a role in pneumonia, dermonecrosis, endocarditis, and sepsis in animal models of S. aureus infection. In mouse models, active immunization with a non-toxigenic form of Hemolysin A or passive immunization with Hemolysin A-specific antisera or monoclonal antibodies (mAbs) significantly reduces the size of skin lesions and prevents dermonecrosis caused by Hemolysin A-producing S. aureus strains.