PHILADELPHIA (KYW Newsradio) — Nearly a year and a half into the COVID-19 pandemic, scientists are still trying to find the origin of the virus that caused it.
The scientific community has lined up behind the theory that SARS-CoV-2, the virus that causes COVID-19, jumped from bats, through an intermediary host, to humans. That intermediary host, though, has not been identified.
In the absence of definitive proof, another theory that was discounted early on, is gaining traction: that the virus escaped from a lab at the Wuhan Institute of Virology (WIV).
"I really don’t go for that theory," said Dr. Susan Weiss, a University of Pennsylvania virologist who has studied coronaviruses for 40 years. "Twice we’ve had viruses go from bats to intermediate species to humans. It would be the default belief."
She allows the lab escape theory cannot be ruled out, as does her colleague at Penn, Dr. Drew Weissman, who developed the mRNA technology that underlies the Pfizer and Moderna COVID-19 vaccines.
Related
"There’s no way to rule something like that out, but I doubt that’s how it happened," he said.
"You’re completely protected," he said of the lab's setup. "There’s an anteroom, where you get dressed and undressed. The procedures are set up so that things like that can’t happen."
A World Health Organization (WHO) study released at the end of March concluded that the most likely scenario was that SARS-CoV-2 had jumped from bats to an intermediary host and then to humans, a phenomenon virologists call zoonosis.
That report, though, has been criticized by more than a dozen countries, including the U.S., as having been hampered by lack of access to complete, original data and samples.
"Together, we support a transparent and independent analysis and evaluation, free from interference and undue influence, of the origins of the COVID-19 pandemic," they wrote in a joint statement. "In this regard, we join in expressing shared concerns regarding the recent WHO-convened study in China."
China’s refusal to cooperate with investigations into the virus' origins lends itself to the alternate theory -- that scientists at WIV were manipulating coronaviruses in what is known as "gain of function" research, and that the result was super-transmittable SARS-CoV-2.
Related
The theory was raised early in the pandemic but was considered so unlikely, it did not get much attention. It still is widely doubted by researchers like Weiss and Weissman. The WHO report called it the least likely scenario.
Recent articles in scientific publications, though, attempt to make the case that the lab escape is, in fact, the most likely scenario.
"It seems to me that proponents of lab escape can explain all the available facts about SARS2 considerably more easily than can those who favor natural emergence," wrote Nicholas Wade in the Bulletin of the Atomic Scientists.
Wade's article came up in the U.S. Senate two weeks ago, when Sen. Rand Paul used it to question National Institutes of Health (NIH) Director Anthony Fauci about whether NIH had funded WIV.
Observers expect to hear more about the lab escape theory after Dr. Steven Quay, CEO of the biopharmaceutical company Atossa, briefs members of Congress on Monday. He will be presenting his paper, which boldly declares “beyond a reasonable doubt that SARS-CoV-2 is not a natural zoonosis but instead is laboratory derived."
Quay and Wade both cite as central -- what Wade’s article refers to as the "smoking gun" for lab escape theory -- a site on the surface of the SARS-CoV-2 virus, which helps the virus invade human cells.
"Of all known SARS-related beta-coronaviruses, only SARS2 possesses a furin cleavage site," Wade wrote.
Weiss says that is incorrect. SARS-CoV-1 did not have such a site, she said, "but lots of other coronaviruses do, including MERS."
Weiss also doubts that SARS2's features could be engineered. She, herself, has tried to manipulate the mouse coronavirus, she said.
"What we found is, you can’t fool Mother Nature. You make something and then it may not behave the way you think it will."
Weiss said there are many signs the virus is naturally occurring, including the discovery of new variants, which show the virus continues to adapt and change through natural selection.
She does agree that, with no definitive proof for either theory, neither can be ruled out.
That would change if an intermediary host that transferred the virus from bats to humans could be found. Wade and Quay suggest if one existed it would have been found by now, but it took more than a year to find that civets spread SARS and nearly a year to find that camels spread MERS, so 17 months is probably too soon to rule out an intermediary host for this virus.
The joint statement on the WHO report calls for a vigorous Phase 2 study of all the evidence.
"With all data in hand, the international community may independently assess COVID-19 origins, learn valuable lessons from this pandemic, and prevent future devastating consequences from outbreaks of disease."
LISTEN on the Audacy App
Sign Up and Follow Audacy
Facebook | Twitter | Instagram