The doctors were not jailed, because luckily CCP need them to work to fight the virus. Some of them died for it already, mostly due to the hard work, insufficient protection CCP provided to the doctors, and in one case at least, intentionally punish the doc by delay his treatment.

Talking about the origin of this virus, this paper of 2015 is quite interesting: https://www.nature.com/articles/nm.3985 . In this paper, the wuhan P4 institute people basically described how they produced a prototype of the 2019 wuhan virus.