Wall Street Journal reported that China was testing on variants of coronavirus when 6 mines became ill cleaning bat guano in a mine, out of which three died. Evidence suggests that China has been researching the variants since then and several WIV researchers became sick in autumn 2019 “with symptoms consistent with both COVID-19 and common seasonal illness”, pointing the possibility that the virus could have been one of natural origin that was brought back to a laboratory in Wuhan intentionally or accidentally and escaped.