4 reasons why a coronavirus leak would be extremely unlikely

Business Insider
2020-05-02 | Since 3 Month

A fringe theory suggests that the new coronavirus leaked by accident from a lab in Wuhan.

Researchers at the Wuhan Institute of Virology (WIV) study infectious diseases, including coronaviruses, and did before the pandemic started. So as questions about how the pandemic started continue to go unanswered, the lab has drawn scrutiny.

Matthew Pottinger, Trump's deputy national security adviser, asked intelligence agencies in January to look into the idea of a Wuhan lab leak, The New York Times reported. But CIA officers didn't find any evidence.

There's a reason for that, according to Jonna Mazet, an epidemiologist at the University of California, Davis, who has worked with and trained WIV researchers in the past.

"I know that we worked together to develop very stringent safety protocol, and it's highly unlikely this was a lab accident," she told Business Insider. Here are four reasons why.

Reason 1: The lab's samples don't match the new coronavirus
The WIV houses China's only Biosafety-level-4 laboratory, which is one of only a dozen in the world. Scientists study the most dangerous and infectious microbes known to humankind in these types of facilities. Some of the institute's researchers, including virologist Shi Zhengli, have collected, sampled, and studied coronaviruses that circulate Chinese bats. In 2013, Shi and her collaborators pinpointed the bat population most likely responsible for spreading SARS, in the Shitou Cave near Kunming.

After her team sequenced the COVID-19 virus, Shi told Scientific American that she quickly checked her laboratory's record from the past few years to check for accidents, especially during disposal. Then she cross-referenced the new coronavirus' genome with the genetic information of other bat coronaviruses her team had collected. They didn't match.

"That really took a load off my mind," Shi said told Scientific American, adding, "I had not slept a wink for days."

Mazet has met and worked with Shi through PREDICT, a pandemic early-warning program started by the US Agency for International Development. The program has trained staff and funded labs in 30 countries, including the WIV, but President Donald Trump shut down PREDICT last fall.

"I've spoken to her recently," Mazet said of Shi. "She is absolutely positive that she had never identified this virus prior to the outbreak happening."

Mazet added that Shi set up a secure, shared database into which PREDICT members could upload their work for public release.

Reason 2: The lab implements rigorous safety protocols
In 2018, US officials raised concerns about safety issues at WIV, according to diplomatic cables obtained by The Washington Post. But Mazet said Shi's work in the lab and in the field was above reproach.

"In the field, they wear extreme personal protective equipment, including multiple layers of gloves, eye protection, full body suits, and masks," she said. (She noted, however, that she has not personally visited the WIV and couldn't speak to all the research done there.) Samples collected from bats, Mazet added, get immediately split between some vials that contain chemicals that deactivate the virus, and other containers that leave the virus alive.
All samples are then dunked into liquid nitrogen on the spot, which freezes them, then the vials are 

disinfected and transported to the lab. There, scientists wearing personal protective equipment (PPE) unload them into a freezer set to minus 80 degrees Celsius.

When the samples are studied later, researchers only use the deactivated, non-infectious ones, Mazet said, adding that the vials with viable virus are locked down in a special area.

Reason 3: The coronavirus is the latest in a long line of zoonotic disease outbreaks
Rather than a leak, the coronavirus is more likely the latest disease to have jumped from an animal host to humans, experts say.

This type of cross-species hop, called a spillover event, also led to outbreaks of Ebola and SARS. Both of those viruses originated in bats, and genetic research has all but confirmed the same for the new coronavirus — a study published in February found that it shares 96% of its genetic code with coronaviruses circulating in Chinese bat populations.

Three out of every four emerging infectious diseases come to us from other species; these pathogens are known as zoonotic diseases. The coronavirus is the seventh zoonotic virus to have spilled over into people in the last century.
The 2009-2010 H1N1 pandemic — swine flu — started in pigs then killed nearly 300,000 people. People have caught bird flus via direct contact with infected poultry. Other pandemic influenza strains, including the 1957 "Asian flu" and the 1968 Hong Kong pandemic, likely started in birds, too.

And in the last 45 years, at least four epidemics have been traced back to bats.

Reason 4: Everyday people are more likely to get infected than researchers who wear protection
The caves and wild habitats in which samples get collected from bats are dangerous places for people, since humans can be exposed to the live viruses circulating in the animals, Mazet said.

Shi's researchers navigate those caves in full PPE; but tourists, hunters, poachers, and other people who rely on animals in some capacity for food or trade wander into such places less protected.
Peter Daszak, president of EcoHealth Alliance (which managed PREDICT's relationship with the WIV), told NPR last week that his colleagues are "finding 1 to 7 million people exposed" to zoonotic viruses in Southeast Asia each year.

"That's the pathway. It's just so obvious to all of us working in the field," he said.

A study published in March 2019 even predicted that bats would be the source of a new coronavirus outbreak in China. That's because the majority of coronaviruses — those that affect humans and animals — can be found in China, and many bats "live near humans in China, potentially transmitting viruses to humans and livestock," the authors said.



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