China filed a patent for a drug seen as one of the best potential weapons against coronavirus the day after Beijing confirmed coronavirus was transmissible to humans. The revelation that it moved so fast fuels concerns about a cover-up of the pandemic when it erupted and suggests that China’s understanding of the virus was far more advanced than the impression given in public. The chairman of the US foreign affairs select committee joined the growing global call for a full, independent inquiry into China’s role, saying, ‘It is quite clear there is an awful lot that we do not know about the emergence of this disease and the responses to it. We all need to learn the lessons of the outbreak so that the international community can respond better in the future.’ Leaked documents showed that China’s officials knew they faced an epidemic but delayed warning the public for six days.