WASHINGTON—Three researchers from China’s Wuhan Institute of Virology became sick enough in November 2019 that they sought hospital care, according to a previously undisclosed U.S. intelligence report that could add weight to growing calls for a fuller probe of whether the COVID-19 virus may have escaped from the laboratory.
The details of the reporting go beyond a State Department fact sheet, issued during the final days of the Trump administration, which said that several researchers at the lab, a center for the study of coronaviruses and other pathogens, became sick in autumn 2019 "with symptoms consistent with both COVID-19 and common seasonal illness."
The disclosure of the number of researchers, the timing of their illnesses and their hospital visits come on the eve of a meeting of the World Health Organization’s decision-making body, which is expected to discuss the next phase of an investigation into COVID-19’s origins.
Current and former officials familiar with the intelligence about the lab researchers expressed differing views about the strength of the supporting evidence for the assessment. One person said that it was provided by an international partner and was potentially significant but still in need of further investigation and additional corroboration.
Another person described the intelligence as stronger. "The information that we had coming from the various sources was of exquisite quality. It was very precise. What it didn’t tell you was exactly why they got sick," he said, referring to the researchers.
November 2019 is roughly when many epidemiologists and virologists believe SARS-CoV-2, the virus behind the pandemic, first began circulating around the central Chinese city of Wuhan, where Beijing says that the first confirmed case was a man who fell ill on Dec. 8, 2019.
The Wuhan Institute hasn’t shared raw data, safety logs and lab records on its extensive work with coronaviruses in bats, which many consider the most likely source of the virus.
China has repeatedly denied that the virus escaped from one of its labs. On Sunday, China’s foreign ministry cited a WHO-led team’s conclusion, after a visit to the Wuhan Institute of Virology, or WIV, in February, that a lab leak was extremely unlikely. "The U.S. continues to hype the lab leak theory," the foreign ministry said in response to a request for comment by The Wall Street Journal. "Is it actually concerned about tracing the source or trying to divert attention?"
The Biden administration declined to comment on the intelligence but said that all technically credible theories on the origin of the pandemic should be investigated by the WHO and international experts.
"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," said a spokeswoman for the National Security Council.
"We’re not going to make pronouncements that prejudge an ongoing WHO study into the source of SARS-CoV-2," the spokeswoman said. "As a matter of policy we never comment on intelligence issues."
Beijing has also asserted that the virus could have originated outside China, including at a lab at the Fort Detrick military base in Maryland, and called for the WHO to investigate early Covid outbreaks in other countries.
Most scientists say they have seen nothing to corroborate the idea that the virus came from a U.S. military lab, and the White House has said there are no credible reasons to investigate it.
China’s National Health Commission and the WIV didn’t respond to requests for comment. Shi Zhengli, the top bat coronavirus expert at WIV, has said the virus didn’t leak from her laboratories She told the WHO-led team that traveled to Wuhan earlier this year to investigate the origins of the virus that all staff had tested negative for Covid-19 antibodies and there had been no turnover of staff on the coronavirus team.
Marion Koopmans, a Dutch virologist on that team told NBC News in March that some WIV staff did fall sick in the autumn of 2019, but she attributed that to regular, seasonal sickness.
"There were occasional illnesses because that’s normal. There was nothing that stood out," she said. "Maybe one or two. It’s certainly not a big, big thing."