++++ This post is mirrored from here
Standard SRI model refers to Suseceptance population ( those who can be infected from the virus ) , Infected (duh) , Recovered/Dead .. by solving differential equations
S = Susceptance population R = Recovered/Dead I = Infected
where α is the r_o value of Covid19 its negative as people get infected the total susecptance population drops (ie people get sick)
here β is the recovery coefficient of Covid19 its negative as infected people either gain immunity or die due to virus ... either way they aren't suceptible to the virus anymore
