The Covid-19 pandemic was ‘more likely than not’ the result of a lab accident, a US Senate committee has concluded.
Since the start of the pandemic, there has been speculation that the virus emerged as a result of a laboratory leak from the Wuhan Institute of Virology (WIV) in China, which collected and manipulated viruses from bald -mouse.
Many prominent scientists have continued to dispute the laboratory leak theory, claiming that a natural overflow event is a more likely explanation.
But the new report says there were “a number of anomalies” in the emergence of Covid-19 naturally compared to other contagious diseases, such as Sars and Mers.
Within six months of the Sars outbreak in 2002, scientists had discovered the species causing the outbreak, but despite widespread searches, a candidate for Covid-19 was never found.
“Nearly three years into the Covid-19 pandemic, critical evidence that would prove the emergence of Sars-CoV-2 is lacking, and the resulting Covid-19 pandemic was caused by an overflow natural zoonotic,” the report said.
The committee also said it was unusual that Covid-19 only spread to humans once or twice over a two-week period, and only occurred in or near Wuhan.
It is unclear how the virus traveled
In other spillover events, jumping between species has happened multiple times and in different places.
The bats that carry the virus closest to Covid-19 live in southern China or Southeast Asia, so it’s unclear how the virus traveled more than 1,000 miles to reach Wuhan, according to The report.
However, WIV had collected over 220 Sars-related coronaviruses, of which at least 100 were never made public. Staff were photographed wearing inadequate levels of personal protective equipment (PPE) when handing over the bats.
There is also evidence that WIV scientists were engaging in advanced coronavirus research designed to predict and prevent future pandemics by collecting, characterizing and experimenting with “high risk” coronaviruses.
WIV also submitted a proposal in 2018 seeking funding to engineer coronaviruses to increase their ability to infect human cells.
The committee also said it was “notable” that early variants of Covid-19 were already well suited for human-to-human transmission.
WIV’s senior coronavirus researcher Shi Zhengli admitted that the team infected humanized mice with a chimeric Sars-related coronavirus, but never published the results.
The report’s authors said the theory that the virus arose naturally “no longer deserves the benefit of the doubt” and said a lab leak was more plausible.
“The result of a research-related incident”
They said: ‘A research-related incident is consistent with early epidemiology showing rapid spread of the virus in Wuhan, with the first calls for help located near the WIV’s home campus in central Wuhan.
“In short, human error, mechanical failure, animal bites, animal escapes, inadequate training, insufficient funding and pressure for results can lead to escape of virulent pathogens, which could, in turn, infect animals and humans and lead to a release of a virus from a laboratory.
“Based…on publicly available information, it seems reasonable to conclude that the Covid-19 pandemic was, more likely than not, the result of a research-related incident…the hypothesis of ‘a natural zoonotic origin no longer deserves the benefit of the doubt.’
The new report comes just a week after scientists claimed to have found evidence that Covid-19 was engineered in a lab.
Professor François Balloux, director of the UCL Institute of Genetics, said this was “the strongest evidence to date against a simple scenario of strict zoonotic origin for Sars-CoV- 2”.