Leading British and US scientists thought it was likely that Covid accidentally leaked from a laboratory but were concerned that further debate would harm science in China, emails show. An email from Sir Jeremy Farrar, director of the Wellcome Trust, on February 2 2020 said that “a likely explanation” was that Covid had rapidly evolved from a Sars-like virus inside human tissue in a low-security lab. The email, to Dr Anthony Fauci and Dr Francis Collins of the US National Institutes of Health, went on to say that such evolution may have “accidentally created a virus primed for rapid transmission...