Table 7.

Brief summary of ESS virulence changes in different disease models and their public health implications

Model type	ESS virulence increases	ESS virulence decrease	Public health implications
Indirectly transmitted infection (simplified HCV model)	ESS virulence increases as treatment rate, rate of late-stage progression, and self-clearance rate increase	ESS virulence decreases as the transmission rate in hosts increases	Under certain conditions, viruses can evolve increases virulence in populations of individuals with higher rates of self-clearance of a virus
Directly transmitted model (simplified SARS-COV-2 model)	When virulence is a function of transmission from symptomatic individuals, virulence increases as a function of recovery rate	When transmission from both symptomatic and asymptomatic individuals is related to virulence, virulence decreases as the recovery rate increases, while considering other parameters for regularization	Whether asymptomatic and/or symptomatic individuals are transmitting has profound implications for the evolutionary trajectory of traits that confer virulence