In this model intranasal inoculated with the strain of interest. Health checks are performed four times a day within the first 72 hours of infection and once per day until termination of the study. Weight is recorded once daily during the course of disease. Lower, non-lethal inoculum challenge can be performed for CFU determination over extended periods of time. Meta-analysis of results for studies comparing experimental vaccine versus control groups in this model indicate improved survival among vaccinated mice.