The Kermack and McKendrick model (1927; 1932; 1933) or SIR model can be used to describe the progress of an epidemic through a population. The S term stands for susceptible individuals, I stands for infectious individuals (those who are infected an who can transmit the disease), and R stands for those who are recovered and now immune to the disease. Determine the number of infected individuals needed for there to be an epidemic. What happens to the progress of the epidemic when you change the number of S or R individuals? What about in populations with and without vaccinations?

### Theory

- Compartment models (Neuhauser, Claudia. Calculus for Biology and Medicine. New Jersey: Prentice Hall, 2000. 587; Stephen P. and John Guckenheimer. Dynamic Models in Biology. New Jersey: Princeton University Press, 2006. 7)
- Simple epidemic model (Neuhauser, Claudia. Calculus for Biology and Medicine. New Jersey: Prentice Hall, 2000. 387)
- Differential equation models for infectious disease (Stephen P. and John Guckenheimer. Dynamic Models in Biology. New Jersey: Princeton University Press, 2006. 183)

### References