Last clue to Covid-19 origins may sit in hospital

China is preparing to test thousands of blood samples from the city of Wuhan as part of the probe into the origins of Covid-19, but as CNN's Nick Paton Walsh reports, the World Health Organization and other foreign experts will not be allowed to analyze the data independently.

Last clue to Covid-19 origins may sit in hospital
China is preparing to test thousands of blood samples from the city of Wuhan as part of the probe into the origins of Covid-19, but as CNN's Nick Paton Walsh reports, the World Health Organization and other foreign experts will not be allowed to analyze the data independently.