How many People may have Contracted COVID-19 and whether any City has Reached Herd Immunity?

It is still hard to know how many people have already been infected with SARS-CoV-2. Epidemiologists have already developed different prediction models that can be used as quantitative projections for the COVID-19. However, these epidemiologic models are impacted by uncertainty due to lack of adequate information regarding the total number of people who have contracted SARS-CoV-2 [1]. One of the reasons for the above challenge is the fact that approximately 35% of people infected with the COVID-19 are asymptomatic [2] and over 81% of those who are symptomatic have mild symptoms [3].