His executive order targeted the elimination of what is called gain-of-function, which studies how viruses become more powerful. The United States funded that sort of research at the Wuhan lab, in the city where the initial outbreak was reported. But a competing theory is that a person somehow came into contact with an infected animal.

US President Donald Trump has signed an executive order banning US-funded virus research amid arguments between America and China about the origin of Covid.

The former President's executive order will immediately halt "any present and all future" US funding for gain-of-function research in countries like China and Iran that lack proper safety oversight