Predicting the impact of asymptomatic transmission, non-pharmaceutical intervention and testing on the spread of COVID19 COVID19

Ira B Schwartz; James H Kaufman; Kun Hu; Simone Bianco

As is common with emerging outbreaks of novel pathogens, the epidemiology of SARS-CoV-2 is not completely determined. Current estimations of the disease basic reproduction number, R 0 , put a realistic value between 2 and 3 [3, 6]. In our analysis, we use a baseline value of R 0 = 2 (as a best case assumption). We also assume that implementations of control reduces transmission by 25% to 50%. The actual parameter values may differ and are still under investigations. However, the parameters we choose reflect a realistic scenario of transmission and are informative with regard to control strategies. Using these best case parameter, we then compute the additional cases that will occur as a function of the time when interventions are removed. The data suggests that decision to remove public health interventions can and should be informed by an analysis such as the one reported here. The fact that the epidemic curve is past its peak does not protect against a second wave so long as a large reservoir of unvaccinated susceptible population remains.