A 2019 video shows scientists from the Wuhan CDC collecting samples in bat caves - but the agency hasn't revealed any findings

• A video from December 2019 shows Wuhan CDC experts collecting virus samples in local bat caves.
• Yet the Wuhan CDC said it did not store or study coronaviruses or bat viruses prior to the pandemic.
• US intelligence is investigating the possibility that the coronavirus leaked from a Chinese lab.

During the World Health Organization's month-long investigation into the origins of the pandemic in January, the Wuhan Center for Disease Control and Prevention told the team that it hadn't stored or studied coronaviruses or other bat viruses before the pandemic.

But a video released by Chinese state media just weeks before officials reported the first cluster of COVID-19 cases in Wuhan casts doubt on that assertion.

The seven-minute documentary, aired December 10, 2019, shows Wuhan CDC staff collecting samples of viruses from horseshoe and pipistrelle bats in caves across China's Hubei province.

"Among all the known creatures, the bats are rich in various viruses inside. You can find most viruses responsible for human diseases like rabies, SARS, and Ebola," Tian Junhua, a Wuhan CDC researcher, says in the video. "It is while discovering new viruses that we are most at risk of infection."

In the last 46 years, at least four epidemics have been traced back to bats in Africa and Asia, which is why infectious-disease researchers study them. In the video, Tian says such work is necessary to "lay a firm foundation for making vaccines."

But now, as more politicians and public-health leaders call for further investigation into the possibility that the coronavirus leaked from a lab, the Chinese footage has gained new attention. Although it does not specify when the shots were filmed, the video indicates scientists from the Wuhan CDC were doing research in bat caves before the pandemic, contrary to what they told the WHO.

The Wuhan CDC also hasn't been transparent about the findings of that research. Since the video's release, the agency has not revealed which viruses Tian's team found (if any), whether those viruses are related to the coronavirus, or where those virus samples are now.

Tian has not spoken publicly about his virus research since the pandemic began, according to the Washington Post. He did, however, co-author a February 2020 study suggesting the coronavirus's genetic code was a close match to other viruses found in bats.

Two Wuhan labs are in the spotlight

The WHO team, in the end, couldn't definitively tell the world anything. Most likely, they said, the virus jumped from a bat to an intermediary animal host, then onto people at a wildlife farm. But the researchers couldn't prove that because they weren't given access to animal samples from the farms in question, nor from the wet market linked to many of Wuhan's first coronavirus cases.

The investigation determined it was "extremely unlikely" that the virus leaked from a Wuhan lab, since they didn't find evidence that any lab in the city - including the Wuhan CDC - was storing viruses closely related to the one that causes COVID-19.

Most proponents of the lab-leak theory tend to focus not on the Wuhan CDC, but on the Wuhan Institute of Virology (WIV) - a lab that did coronavirus research prior to the pandemic. Three WIV staff were hospitalized with COVID-like symptoms in fall of 2019, according to a US intelligence report obtained by the Wall Street Journal. It's plausible, though, that the coronavirus had already begun to spread in Wuhan by then.

The Wuhan CDC, meanwhile, spearheaded the city's initial coronavirus response; it has labs that study AIDS and influenza.

Still, some researchers suggest the Wuhan CDC merits further investigation, since WHO investigators spent only hours at each lab in the city. That's not enough time to conduct a full audit of a facility or verify the viruses being stored there.

Last year, Chinese scientist Botao Xiao wrote in a paper that the Wuhan CDC "hosted animals in laboratories for research purposes," including bats. He suggested that an unsuspecting scientist might have accidentally tracked out a virus from one of those animals. But Botao later withdrew the paper because he said it lacked sufficient proof.

Yet Richard Ebright, a microbiologist at Rutgers University, told Insider last year that he agreed with Botao. In an email, Ebright pointed to the December 2019 video as evidence that Wuhan CDC lab staff had "unsafe operational practices (bare skin on faces, bare skin on wrists, no goggles, no face shields)."

The WHO team, though, said they were satisfied with the Wuhan CDC's safety protocol. The agency told investigators that none of its staff had gotten sick with any illness resembling COVID-19 in the months prior to December 2019, or tested positive for coronavirus antibodies. According to WHO leaders, however, investigators had difficulty accessing raw data to corroborate those assertions.

Close calls with bats

In the Chinese video, Tian and his colleagues are shown wearing protective suits, goggles, gloves, and masks. He explains why: "If our skin is exposed, it can easily come in contact with bat excrement and contaminated matter, which means this is quite risky."

Still, Ebright said he thinks the staff in the video were "collecting bat coronaviruses with inadequate PPE."

There's no indication that Tian or his researchers got sick following the work depicted in the video. But Tian has said in the past that he had close calls with bats. According to the Washington Post, Tian told a local news outlet in 2017 that he'd gotten bad blood on his skin multiple times and once had to quarantine after getting splashed with bat urine.

In his retracted paper, Botao described a Wuhan CDC researcher who was known for collecting viruses and had been forced to quarantine after bats peed on him. That researcher is not named in the paper, though.

Despite questions swirling about possible connections between Chinese labs and the pandemic's origin, it's worth noting that everyday people - farmers, miners, and tourists who explore caves without protective equipment - are often more likely to get exposed to bat viruses than scientists with lab experience.

Peter Daszek, a disease ecologist with EcoHealth Alliance who was a member of the WHO investigation team, told NPR in April 2020 that "1 to 7 million people" are exposed to zoonotic viruses in Southeast Asia each year.