(STL.News) The head of the World Health Organization (WHO) says further investigation is needed to conclusively rule out a theory that Covid-19 emerged from a laboratory in China.
Tedros Adhanom Ghebreyesus said on Tuesday that although a laboratory leak is the least likely cause, more extensive research is needed.
The virus was first detected in Wuhan, in China’s Hubei province, in late 2019.