Monday, 20 March 2023 15:34

The key to Covid’s origin lies in Beijing, not Wuhan

An eyewear market above the Huanan Seafood Market in Wuhan, China, on February 6, 2023.

There’s one entity that is best poised to answer one of the most important scientific questions of our time: How did the Covid-19 pandemic originate? And it’s not the virologists scouring genetic data from live animal wet markets in search of a zoonotic spillover, nor is it the lab leak proponents debating furin cleavage sites and battling over translations of old emails.

It’s the Chinese government — and that, more than any other fact, is why it looks increasingly unlikely that we’ll ever find an answer that all parties can agree on to the question of what caused the worst pandemic in a century.

That’s one main takeaway from several media reports published over the past day about a new analysis of genetic data taken from the Huanan Seafood Wholesale Market in Wuhan, China, where the first human cases of Covid-19 emerged more than three years ago. The analysis, first reported by the Atlantic, shows that raccoon dogs that were being illegally sold in the market may have been carrying the novel coronavirus at the end of 2019.

A zoonotic origin — meaning from animals, which is how nearly all emerging diseases first spread to humans — demands that scientists identify the equivalent of an animal species “patient zero,” where the new virus can incubate and evolve before passing to humans.

If it is true that raccoon dogs kept in close quarters with human beings were infected and shedding the virus before people first started getting sick, it “really strengthens the case for a natural origin” of the pandemic, as the Emory University virologist Seema Lakdawala told the Atlantic.

But it wouldn’t be a Covid origin story without ongoing mysteries both scientific and political. Even if raccoon dogs were carrying the virus at that time, they may not be the original animal reservoir. In the 2003 SARS-1 outbreak, scientists originally pointed the finger at civet cats, only to later discover that the true reservoir was horseshoe bats.

The new analysis in the Atlantic story has yet to reach even the preprint stage of scientific publication, meaning it hasn’t been peer-reviewed yet, though several of the researchers did present their findings to the World Health Organization (WHO) on March 14.

Then there’s the question of the genetic signatures themselves. The data was posted without fanfare earlier this month on an open-access database called GISAID by Chinese researchers connected to the country’s Center for Disease Control and Prevention.

Florence Débarre, an evolutionary biologist at the French National Center for Scientific Research who had been scanning GISAID for data from the Huanan outbreak, noticed the new genetic signatures on March 4 and eventually alerted a group of researchers who had been studying the market.

Yet when the group reached out to the Chinese scientists who had posted the data, the sequences suddenly disappeared from GISAID, and no one knows who or why they were taken down.

Like so much else around the origins of Covid, it’s a mystery — one that can likely only be answered by the Chinese government, which for years has seemed bent not on discovering the pandemic’s true beginning but on proving that, whether zoonotic or lab-borne, the virus that has killed millions of people around the world did not originate in China.

When politics trump science

Even under the best, most cooperative circumstances, identifying the animal reservoir of a new virus is really, really hard.

It took scientists 14 years to finally track down the origins of the 2003 SARS outbreak to a remote horseshoe bat cave in China’s Yunnan province. We still don’t know the original animal reservoir of the Ebola virus, which was first identified in humans in 1976.

But the circumstances around the investigation of the origins of SARS-CoV-2 have neither been good nor cooperative.

There’s a reason that the Huanan market has been the focus of so much speculation on Covid’s origins: A wet market, where animals from many different species are kept in close quarters with human beings, is the perfect environment for new viruses to jump from animals to humans. For instance, while the SARS-1 virus from 2003 originated in bats, it seems to have jumped to humans via the intermediary species of civet cats kept in similar wet markets in China’s southern Guangdong province, where the first human cases were detected.

Early epidemiology indicated that a number of the first human Covid-19 cases had a connection to the Huanan market. Had an open, thorough investigation occurred at the time, when data was still fresh, scientists might have gotten a clear answer one way or another.

But from the start, the Chinese government interfered with efforts by both Chinese and international experts to study the pandemic, including its origins. Reporting by the AP found that even as WHO officials were publicly praising China’s cooperation, behind the scenes they were complaining about lack of access and a refusal to share data.

Within months of the beginning of the pandemic, the Chinese government imposed restrictions on academic research into the origins of the novel coronavirus. Beijing maintained that no illegal animals — like raccoon dogs — were being sold at the market, even though researchers in June 2021 published a study documenting that sales were occurring up through late 2019 at the least.

China’s intransigence wasn’t unusual — countries are rarely eager to confirm that they’re the source of a deadly disease — but it went beyond the norm. International investigators weren’t permitted to see the market until more than a year after the pandemic began and a WHO-affiliated team was allowed a highly choreographed and controlled visit.

The resulting report that came out of the Wuhan visit, which dismissed the possibility of a lab origin, pointed the finger at some kind of zoonotic spillover while concluding that it was unlikely that the spread started at the market, which surprised many experts.

It also found that it was “possible” that the virus had been introduced via contaminated frozen food products from abroad. While few experts took that possibility seriously, it fit a narrative the Chinese government had been pushing, against nearly all evidence, that the pandemic had in fact not originated in China.

“China just doesn’t want to look bad,” Filippa Lentzos, a biosecurity expert at King’s College London, told Science last August. “They need to maintain an image of control and competence. And that is what goes through everything they do.”

That obfuscation makes it harder to know what to make of the new coronavirus analysis. The samples had been looked at before by the same group of Chinese researchers, but they concluded in a February 2022 preprint that “no animal host of SARS-CoV-2 can be deduced” and that any coronavirus genetic material had likely been brought in by humans first, not animals.

George Gao, the former director of China’s CDC and the lead author on that preprint, told Science yesterday that the sequences were “[n]othing new,” and he didn’t explain when asked why the data was uploaded and then quickly removed from GISAID. But whether or not the new evidence does prove a major clue to a zoonotic origin, as the international team of researchers is claiming, it seems clear that with more cooperation, scientists could have been looking at raccoon dogs a year or more ago.

“The big issue right now is that this data exists and that it is not readily available to the international community,” Maria Van Kerkhove, the WHO’s Covid-19 technical lead, told reporters on Friday. “This is first and foremost absolutely critical, not to mention that it should have been made available years earlier, but that data needs to be made accessible to individuals who can access it, who can analyze it and who can discuss it with each other.”

The irony is that by making it so difficult to properly investigate a zoonotic origin of Covid, the Chinese government has created a vacuum that has been filled by claims on all sides, including the much more damning accusation that the pandemic was the result of a lab error at the Wuhan Institute of Virology.

What was once dismissed as a conspiracy theory has become surprisingly mainstream. Last month, the Department of Energy reported that it believed with “low confidence” that the virus had originated in a lab, while polls released this week found that Americans overwhelmingly believe the virus was lab-borne.

SARS redux

For those of us who lived through the original SARS epidemic in 2003, this all feels eerily familiar.

Chinese authorities suppressed early reports of what would be SARS cases in southern China in early 2003, and it wasn’t until the virus spread to Hong Kong — then, if not now, much more independent and open to the world — that the full extent of the outbreak became impossible to deny.

Even then, the government tried to censor the fact that the virus was spreading in the capital of Beijing. The Chinese government was only forced to come clean when a 71-year-old doctor named Jiang Yanyong contacted my then-colleagues at Time magazine to tell them that there were far more SARS cases than official numbers showed.

Beijing was supposed to have learned from its experience with SARS, and in some ways it did. China in 2003 had no equivalent to the CDC, and it struggled to respond to outbreaks once they could no longer be ignored. For all the many problems with its zero-Covid strategy — especially once the highly transmissible omicron variant emerged — the Chinese government was able to control its spread as few other countries could, the US very much included.

Chinese scientists deserve credit for doing much of the early work on identifying and sequencing the novel coronavirus, and for sharing much of that information with the rest of the world, enabling pharma companies to get an early start on vaccine development.

But when it comes to being forthright about how the pandemic might have started, it appears that China has learned nothing since 2003. If anything, things have gotten much worse.

International media access to China is far more limited than it was 20 years ago, making it that much harder to know what is actually happening within its borders. China’s president, Xi Jinping, is far more powerful than his predecessors Jiang Zemin and Hu Jintao in 2003, and government control is far more personalized, making it that much more dangerous to reveal anything that might put Xi’s rule in a bad light.

At this point, a clear answer on Covid’s origins would have to come from inside China, but revealing sensitive information would be incredibly dangerous — as the rest of Jiang Yanyong’s story shows.

After he blew the whistle on SARS, Jiang was hailed by his country as a hero. But in 2004, Jiang wrote a letter to the central government calling on it to acknowledge that the 1989 crackdown of pro-democracy protesters in Tiananmen Square had been a mistake. Jiang had been in Beijing on the night of June 4, 1989, treating scores of wounded civilians and protesters at the No. 301 Military Hospital.

As a military doctor, he was used to treating injured soldiers, but “lying before me this time were our own people, killed by children of the Chinese people, with weapons given to them by the people,” as he recalled in his letter.

Despite his hero status, Jiang and his wife were detained after the letter was released, and he was required to undergo interrogation and indoctrination sessions. He was barred from leaving China for years, and underwent frequent monitoring and harassment by the authorities. He was all but erased from public consciousness.

As a young doctor in China’s military, he was nicknamed “Brave Jiang” for his willingness to take on the most difficult cases. Jiang — who died this week — was brave when he stood against official lies during SARS, and brave when he continued to fight for the truth about Tiananmen, despite all it cost him.

The question of Covid’s origins will continue in the pages of scientific journals and within the halls of power. Unless another brave Jiang emerges, we may never know the definitive answer.