As seen in Figure 1 , the transfer rates of people from the exposed classes, E and E m , to the infectious classes, I and I m , are vE and vE m . Infectious individuals can move to group D, at rate mI and mI m , when they die from infection or to group R, at rate dI and dI m , upon recovery. The mean times in the infectious classes, I and I m , are 1=(dzm). Hence, the infectious fraction d=(mzd) recovers and the infectious fraction m=(mzd) dies as a consequence of this disease. We assume that there is homogeneous mixing between groups and that contact activity levels remain normal throughout the epidemic. We define t 0 as the beginning of the epidemic. Movement of individuals between mask and non-mask groups depends upon the number of pandemic (H1N1) 2009 cases in the population. A specified percentage of the population starts wearing masks as the number of infected people increases.