An SEIR Model for Assessment of Current COVID-19 Pandemic Situation in the UK

Peiliang SUN; Kang Li

By curve-fitting the results illustrated in Figure 6 , the estimate of the infection rate β is around 0.41. The basic reproduction ratio R 0 can be estimated by calculating S(∞) − S(1) while setting E(1) = 1, ∆E(t) = 0. In our estimate R 0 ≈ 8.8 which is much larger than the results obtained in other published papers. However if we assume anyone who is infected by the virus will be under quarantine 7 days after s/he becomes infectious, then our model estimate for R 0 ≈ 2.8-3.6 which is comparable to the current popular estimates of R 0 reported in the literature [10] . The reason for our estimated R 0 being much larger than the R 0 estimates reported in the literature might be due to that there is a large proportion of people who only got mild symptoms or even were asymptomatic. They can spread the virus before symptom onset till recovery over a long period of time before the lockdown measure was put in place.