Intranasal instillation with the strain of interest is performed on animals that are anesthetized with Isofluran. The inoculation volume does not exceed 50 uL and is deposited into the nares of mice while held in a supine position. Health checks on mice are performed four times a day within the first 72 hours of infection and once per day until termination of the study. Weights are recorded once per day during the course of disease. Typically mice succumb to infection within 24-48 hours. Lower, non-lethal inoculum challenge can be performed for CFU determination over extended periods of time. Figure 1 shows a meta-analysis of study results with an experimental vaccine (n=68) versus control (n=25) in the S. aureus pneumonia model.