We examine the change in shape of t

We examine the change in shape of the disease
wave under variation of the contact and recovery rates.
Figs. 1 and 2 represent the shape of the wave for
the different contact rates. The shape of the wave is
shown in Figs. 3 and 4 for the different recovery rates.
In all of these cases, both front and back solutions
show exponential types of behaviour. The exponential
decrement of the front solutions exhibits a rather small
change.