A paper published online June 10, 2015, and co-authored by Dr Ralph Baric (University of North Carolina Chapel Hill) and Zhengli Shi (Wuhan Institute of Virology) reveals that only two mutations are necessary in the spike protein region of a non-infectious bat coronavirus (HKU4) to make it infectious to humans via ACE2 receptor. Thus coronaviruses could jump directly from bats to humans! [1]
In 2002 Ralph Baric et al patented the method for making coronaviruses infectious to humans via the ACE2 receptor.