From the Abstract: "The Simple Epidemic Model uses three states to describe the spread of an infection: the susceptible (S), the infected (I), and the recovered (R). This model follows the trend of an infection over time and can predict whether an infection will spread. Using this model, epidemiologists may calculate the percentage of the population that needs to be vaccinated in order to provide a population immunity from a disease. This study will compare the vaccination percentage required for herd immunity to measles, mumps, and rubella against the current percentage of vaccinated individuals."
University of South Florida
University of South Florida Scholar Commons: https://scholarcommons.usf.edu/
Undergraduate Journal of Mathematical Modeling: One+Two (Spring 2020), v.2 issue 2