Three employees at a lab in Wuhan, China, became sick and required hospitalization in November 2019, according to a previously undisclosed U.S. intelligence report cited by The Wall Street Journal.
The finding comes amid growing calls from some scientists for a more thorough investigation into the pandemic's origin, including the possibility that the virus originated in a lab. Another common theory is that the virus jumped from an infected animal to humans.
A Jan. 15 fact sheet issued by the U.S. State Department found three scientists at the Wuhan Institute of Virology developed "symptoms consistent with both COVID-19 and common seasonal illness" in November 2019 — the period many epidemiologists and virologists said they believe is when the virus first began circulating in China.
The Biden administration declined the Journal's request to comment on the fact sheet, which was issued under the Trump administration, but said the World Health Organization and other international experts should investigate all technically credible theories on the pandemic's origin.
"We continue to have serious questions about the earliest days of the COVID-19 pandemic, including its origins within the People's Republic of China," a spokeswoman for the National Security Council told the Journal.
State Department spokesman Ned Price said the fact sheet "did not draw any conclusions" about COVID-19's origin but instead "focused on the lack of transparency surrounding the origins."
The WHO has previously said it's "extremely unlikely" that the virus leaked from the Wuhan research lab. On May 24, U.S. Health Secretary Xavier Becerra called on the organization's decision-making body, the World Health Assembly, to launch a follow-up investigation into the pandemic's origins, reports The Washignton Post.
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