5: The SIR Model and its Variants (pt 2)

Question 1

the SEIR model

Answer 1

straight-forward extension of SIR model

new compartment added (E for exposed)

• fixing the issue of no latency period
• people don’t move immediately from susceptible to infectious but susceptible to exposed where they aren’t infectious yet

Question 2

the SEIRS model

Answer 2

relaxing the assumption that immunity goes away

not adding a new compartment but a new transition from recovered to the susceptible compartment

you go from susceptible to exposed to infectious to recovered back to susceptible