Nearly 10 months after reports surfaced of a new coronavirus in Wuhan, China, scientists still do not know how it originated. Most scientists believe the virus, called SARS-CoV-2, jumped from an animal to humans. In February, an analysis published in the journal Nature found the new coronavirus had a genome 96 percent similar to one found in bats, suggesting it occurred naturally. But two studies released in May and September support the idea that Wuhan’s Institute of Virology might have genetically engineered the virus.
In the May study, Alina Chan, a molecular biologist at the Broad Institute of MIT and Harvard, and colleagues noted that when a virus hops from one species to another, it changes rapidly to adapt to its new host. When the novel coronavirus jumped from humans to minks at European fur farms, it mutated in the animals immediately. “You actually see the rapid evolution happening,” Chan told Boston magazine. “Just in the first few weeks, the changes are quite drastic.”
But the coronavirus has barely mutated in humans since the earliest known cases, causing Chan to suspect someone adapted it for human transmission from the start. She acknowledged the mutations might have arisen in an earlier host species, where they happened to mirror the genetics to infect humans. But most mutations make it easier for a virus to thrive in its current host, not an unknown one.
The virus could also have circulated undetected among humans for months. In that case, stored samples should provide a trail of mutations, Chan said. So far, scientists have found nothing.
Another paper released Sept. 14 said SARS-CoV-2 possesses some unusual genetic features that suggest a laboratory modification. The study found the virus contains a protein site that makes it more contagious and does not typically occur in the wild.
The lab theory continues to draw criticism, however. Andrew Preston, an expert in microbial pathogenesis at the University of Bath, accused the researchers of bias. “The language of the report is reminiscent of a conspiracy theory,” he told Newsweek.
A group of public health scientists published a statement in The Lancet in March denying the virus escaped from a lab: “We stand together to strongly condemn conspiracy theories suggesting that COVID-19 does not have a natural origin.”
Other experts note neither of the papers has undergone peer review, in which fellow researchers vet a study before publication. But the authors say peer-reviewed journals censor research suggesting an unnatural origin of the virus, so evidence never gets to the public.
Some scientists might want to quash theories that COVID-19 came from a lab, Richard Ebright, a Rutgers University microbiologist, told Boston: “Avoiding restrictions on research funding, avoiding implementation of appropriate biosafety standards, and avoiding implementation of appropriate research oversight are powerful motivators.”
If the virus originated in a lab, that doesn’t mean someone released it intentionally. The Wuhan facility is one of dozens of labs around the world where scientists research ways to counteract deadly pathogens by altering them to make them more lethal or contagious. And China has a history of runaway diseases: SARS, a coronavirus that spread in humans in 2003, escaped from a Beijing lab twice, said Steven Mosher of the Population Research Institute in Virginia.
The studies do not prove the virus originated in a lab, but researchers must continue to investigate the possibility, Chan said: “We need to find where this came from, and close it down.”