Questions about COVID-19 origin intensify

President Joe Biden on Wednesday asked U.S. intelligence agencies to “redouble” investigations into where the novel coronavirus came from and report back within 90 days. Earlier this week, a Wall Street Journal report based on newly revealed U.S. intelligence found three workers at a Chinese laboratory in Wuhan sought hospital treatment for symptoms consistent with COVID-19 back in November of 2019. China has denied the virus leaked from a lab in the city.

Wasn’t there already an investigation? Earlier this year, a team with the World Health Organization visited China to begin a probe into the origin of the virus. The team reached no conclusions but declared it highly unlikely that the virus could have escaped from a laboratory. But critics say that assessment was based on very limited information and no data from the lab in question. Many have accused China of refusing to fully cooperate in investigations.

Dig deeper: Read Heather L. Frank’s report about the resurfacing question of COVID-19’s beginnings.