Elisha B. Are

Results 2 comments of Elisha B. Are

**Re: vaccination** - I think we should separate 'vaccine-induced immunity' and 'immunity due to previous infection' from the outset. i.e. `dS/dt= ... -v(t)S, dV/dt= ... +v(t)S` instead of combining both...

Another change we might consider adding is a separate class for ** asymptomatic individuals**: If E2 is pre-symptomatic individuals, then we can have `dE2/dt =... -cE2, dI1/dt=...+ c*(1-b)E2, dI2/dt=...+ c*bE2`...