In 2015, Dr Stone was studying CovonaVirus in bats and rats, She felt that the virus was too dumb; so, she decided to give it a helping hand. She injected the ACE2 gen coding into the virus, and a star was born.
In public, a great scientific break-thru. In private, a perfect bio WMD.
After great criticism from the scientific community, her program was terminated (or moved underground). But nobody know what happened to the research materials and animals. Some were adopted as pets. Some were breed and sold to meat market. Some were raised in the lab for further work.
Immediately after the outbreak in late 2019. The WuHan P4 lab identified the 2019 nCov gene sequence in record time and suggested HIV antiviral drugs for treatment.
Some drugs targeting HIV and Ebola are partially effective against some cases. Unfortunately, with huge human hosting environment and multi (4+) generation mutations. 2019 nCov will be with us for some time.
Official estimate is now 20,000. But many carriers are unable to win the lottery of this group. So, as much as 10x more are send home to join their family. Another 20x might be carriers without symptoms.
So, we will reach millions in no time.