We describe and analyse by elementary means some simple models for disease transmission with vaccination and treatment. In particular, we give conditions for the existence of multiple endemic equilibria and backward bifurcations. The results are applicable to epidemic models in which demographic effects are ignored, but there is temporary immunity following recovery from infection.
- Backward bifurcation
- Temporary immunity
ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics