Researchers believe corona origins in the laboratory are possible. Method used was actually developed to distinguish natural epidemics from those that could be due to intentional biological attacks.
Criteria that were given different weightings in the evaluation included, for example, the concentration in the environment or the speed of spread. Based on the data, each of the points is assigned a value between 0 and 3, where 0 stands for "no data", 1 for "uncertain", 2 for "obvious abnormalities" and 3 for "clear indications"