Top World Health Organization officials say they'll keep trying to learn how COVID-19 began but have run up against a lack of full cooperation from China.
"WHO has not abandoned studying the origins of COVID-19. We have not. And we will not," said Maria Van Kerkhove, WHO's technical lead for COVID-19.
"But we need cooperation from our colleagues in China to advance this," she said Wednesday. "I do also want to mention that through the work of studying the origins, it is very difficult."