Where Did Covid Come From?
Investigator Foreshadows Fresh Clues
By Jason Gale
February 7, 2021, 12:38 AM GMT
WHO inquiry may yield
new data from weekslong probe in China
Understanding origins
may help mitigate risk of more pandemics
Where Did SARS-CoV-2 Come From?
Scientists probing the origins of the coronavirus are
wrapping up a lengthy investigation in China and have found “important clues” about a Wuhan seafood
market’s role in the outbreak.
Peter Daszak, a New York-based zoologist assisting the World
Health Organization-sponsored mission, said he anticipates the main findings
will be released before his planned Feb. 10 departure. Speaking from the
central city of Wuhan, where Covid-19 mushroomed in December 2019, Daszak said
the 14-member group worked with experts in China and visited key hot spots and research centers to uncover “some real
clues about what happened.”
Investigators want to know how the SARS-CoV-2 virus -- whose
closest known relative came from bats 1,000 miles away -- spread
explosively in Wuhan before causing the worst contagion in more than a century.
Daszak said the investigation heralds a
turning point in pandemic mitigation.
“It’s the beginning of hopefully a really deep understanding
of what happened so we can stop the next one,” he said over Zoom late
Friday. “That’s what this is all about -- trying to understand why these
things emerge so we don’t continually have global economic crashes and horrific
mortality while we wait for vaccines. It’s just not a tenable future.”
The WHO was asked in May to help “identify the zoonotic source of
the virus and the route of introduction to the human population, including the possible
role of intermediate hosts.”
Lab Theory
The lack of a clear pathway from bats to humans has
stoked speculation -- refuted by Daszak and many other scientists -- that the
virus might have escaped from the Wuhan Institute of Virology, a maximum
bio-containment laboratory studying bat-borne coronaviruses.
Scientists visited the lab and asked Shi Zhengli, who has
collected and analyzed these viruses for more than a decade, about the research
and the earliest known coronavirus cases.
“We really have to
cover the whole gamut of key lines of investigation,” Daszak said. “To be fair
to our hosts here in China, they’ve
been doing the same for the last few months. They’ve been working behind the
scenes, digging up the information, looking at it and getting it ready.”
The work has been “collaborative,” with Chinese
counterparts helping mission investigators dig deeper for clues, he said.
“We sat down with them every single day and went through
information, new data, and then said we want to go to the key places,”
the British scientist said. “They asked for a list. We suggested where we
should go and the people we should meet. We went to every place on that list and they were really
forthcoming with that.”
Daszak is one of 10 independent experts assisting the WHO mission. The agency also has
five staff members participating, and the UN’s Food and Agriculture
Organization and the Paris-based World Organization for Animal Health have two
each.
Joining Threads
Mission delegates worked in three groups that focused on the
potential involvement of animals, the epidemiology or spread of the disease,
and the findings from environmental sampling. Genetic sequencing
data are helping investigators identify threads linking the information across
patients and wildlife, Daszak said.
“My feeling is we
will be able to say something of some value at the end of this trip -- quite a
lot of value, but I don’t want to get into what that’s going to be or which way
it points,” he said, adding that the group’s findings are confidential until
they are released publicly.
Daszak, who was focused on the animal side, said his trip to
the Huanan fresh produce market in central Wuhan was especially useful.
The so-called wet
market sold mostly seafood, as well as meat that included freshly prepared
wildlife. It was a focus early in the outbreak, when cases occurred among
workers and shoppers, suggesting it might have been where the virus jumped from
animals to humans.
‘Important Clues’
Subsequent research found earlier cases among people not
linked to the market, undermining that theory. Investigators looked further
and found “important clues” about the market’s role, Daszak said, declining
to elaborate.
“Right now, we’re trying to tease everything together,” he
said. “We’ve looked at these three strands separately. Now we’re going to bring
it together and see what everything tells us.”
While the food market was shuttered and cleaned
almost immediately after cases were recognized, “it’s still pretty intact,”
Daszak said. “People left in a hurry and they left equipment, they left
utensils, they left evidence of what was going on, and that’s what we looked
at.”
Scientists in China who took environmental samples inside
the market identified sites where traces of SARS-CoV-2 were detected, he said.
Investigators also benefited from greater understanding of Covid-19.
“We know now what we didn’t know then -- that for every sick case, there were others
that were asymptomatic or difficult to distinguish from a cold or cough,”
Daszak said. “And so it’s not unexpected that there would have been other cases
other than ones that got into hospital. But how many others, when did this
start? That’s the sort of thing we’re still working on.”
Viruses are passed along “convoluted rivers of emergence” and tracing that journey is
complicated and will take “a really long time,” Daszak said. “What I have seen
already tells me that there are some
real clues about what happened, and I hope that we’ll be able to make a
solid explanation of that by the end of this trip.”
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