Fig. 1

A flow diagram of the SCLAIV+D+response model with its 8 flow parameters identified by numbers 1–8 plus an asymptomatic infection parameter 9. The 8 drivers identified by lower case Roman letters a-h are either zero (apart from surveillance), a positive constant or have the form of a switching function, as described in the text. We have generalized the disease-induced natural mortality flow rate 8 from being a constant to include the possibility of driving (h) the rate down to account for improvements over time in treatment and therapeutics