2.) Consider an SIR.S model: dS dt d.I dt d.R Suppose a vaccination program is implemented, which effectivly moves a number, oS, of susceptibles to the R class per unit time. (a) Write down the SIRS model with vaccination included. (b) Determine the steady states of this vaccination model and when they are stable. (c) Comment on how the results of this model differ from the model with no vaccination