COVID-19 researchers find evidence of animal origins at Wuhan market, possible link to raccoon dogs
The World Health Organization on Friday urged Chinese health authorities to release SARS-CoV-2 genetic sequences that recently disappeared from an international database after an analysis of the data found they provided new evidence pointing to an animal origin for the virus COVID-19 Pandemic.
The appeal comes after a group of scientists outside of China analyzed genetic sequences of SARS-CoV-2 viruses originally uploaded to the Global Initiative on Sharing Avian Influenza Data (GISAID ) had been discontinued. The database is a website that allows scientists worldwide to access and share genetic sequencing and other data.
The data comes from samples collected around Wuhan’s Huanan Animal Market in early 2020, which investigations by US and Chinese authorities had pointed to as a potential early epicenter for the outbreak.
Analysis of these samples revealed “molecular evidence” from animals such as raccoon dogs at the market, mixed with swabs from the same sites that revealed shedding of the virus itself at the market.
Raccoon dogs are a species susceptible to SARS-CoV-2 infection, which may have served as an intermediate host and transmitted the virus to humans from bats or some other source. However, the samples only indicate that both raccoon dogs and the virus were present in the market; there is no direct evidence that the species was the carrier.
“We must clarify that the virus has not been identified in any animal at the market or in animal samples from the market, nor have we actually found the animals that have infected humans. This provides clues. It provides clues to help us understand what might have happened,” WHO’s Maria Van Kerkhove told reporters on Friday about the findings.
This new data prompted a meeting of the WHO Scientific Advisory Group on the Origins of Novel Pathogens on Tuesday for the international scientists to present their analysis, as well as with the Chinese CDC researchers who originally published the data.
It’s not clear why the records disappeared from the GISAID database after they were released last month, or why Chinese researchers waited three years to release the data.
The data were originally released by the Chinese researchers as part of work on a paper originally published in preprint last year.
Researchers at China’s CDC released a preprint last year, which is currently “under review”, and concluded that the Huanan market “may have acted as an amplifier” for the spread of the human-marketed virus.
“We have been informed by GISAID that the data from China CDC will be updated and expanded. But we have again directly requested China CDC to make this data fully accessible. And that remains absolutely fundamental,” said Van Kerkhove.
George Gao, the lead author of the preprint and former head of China’s CDC, downplayed the importance of the new analysis to Science magazine. Gao said it was “known that there was illegal pet trafficking and therefore the market was closed immediately.”
Gao declined to comment to CBS News as to why the sequences were initially released and then disappeared, deferring the comment to GISAID.
In a statement, GISAID denied that it was deleting records from its database. Data “may become temporarily invisible” from time to time when revisions are needed to improve or correct data, GISAID said.
“In order to continuously improve the quality of the datasets, data providers regularly update their datasets, such as when higher-resolution sequences or additional metadata become available or when review is required,” a GISAID representative said in an email.
Questions about the new analysis, first reported by The Atlantic, also remain unanswered. For example, Van Kerkhove declined to provide further details on how and which other animals were identified in the sequence analysis, deferring comment to the researchers.
French scientist Florence Débarre, named by The Atlantic as the researcher who originally discovered the sequences, did not respond to a request for comment.
On twitterDébarre wrote that they “did not intend to communicate results until our report is complete. Completing the report is my current priority.”
But even if Chinese health authorities re-release the sequences they removed from GISAID, Van Kerkhove warned that far more research would be needed to understand whether the origins of COVID-19 are conclusively linked to animals sold at the market could be brought.
“We have repeatedly asked to conduct studies in other markets in Wuhan and in Hubei and across China. We have repeatedly asked for studies to trace these animals back to their farms of origin, so we can go back in time and actually see where the animals came from and if tests were done,” said Van Kerkhove.
While scientists have discovered evidence to suggest so COVID-19 likely had zoonotic origins – the virus originated from animals that infected humans, much like previous viruses – some US intelligence elements completed that it is plausible that the pandemic arose from a laboratory accident.
“Based on my initial analysis of the data, I concluded, and I still believe today, that this indicates that COVID 19 was the result of an accidental laboratory leak rather than the result of a natural spillover event,” said the former Trump executive. Administration CDC Director Dr. Robert Redfield was speaking at a hearing organized by House Republicans earlier this month.
In an interview with CBS News on Thursday, Dr. Anthony Fauci, who led the US response to the pandemic, said it’s possible we’ll never get a definitive answer as to where COVID came from.
“There’s really no definitive proof,” he said. “We may never know for sure.”