One shows for the first time how the first human cases clustered in a small radius around the Huanan seafood market in the winter of 2019. More precise analysis of smears taken from floors, cages and stalls traces the virus to stalls in the southwest corner of the market, where animals that can harbor Covid were sold for meat or fur at the time. A second study claims to have pinpointed the exact date of the first animal-to-human infection – November 18, 2019 – after genetic analysis of hundreds of samples from the first human carriers. They also say they found evidence that another first-generation strain spread to the wet market—which, if true, would place both original lineages within its walls. Until recently, the only Covid cases linked to the market were Lineage B, which was believed to have evolved after Lineage A. Proponents of the accidental lab spill hypothesis used this as evidence that the virus only reached the market after it evolved elsewhere in Wuhan. One of the experts involved in the new studies, virologist Professor David Robertson, from the University of Glasgow, said he hoped they would “correct the false record that the virus came from a laboratory”. But critics have played down or completely disputed the findings and warned that both studies were carried out by the same group of academics who regularly support the natural origin theory. The question of whether the global outbreak started with a spill from wildlife sold on the market or leaked from a Wuhan laboratory just eight miles across the Yangtze River has fueled intense debate about how to prevent the next pandemic. Now, two new studies show a natural diffusion in the Huanan wildlife market. Positive swab samples of floors, cages and stalls also trace the virus to stalls in the southwest corner of the market (bottom left), where animals with the potential to harbor Covid were sold for meat or fur at the time (bottom right) The question of whether the global epidemic started with a spill from wildlife sold on the market or leaked from a biochemical laboratory has sparked intense debate about how to prevent the next pandemic. Due to shady practices and a high risk of cross-species contamination, the wet market was initially thought to be the source of the outbreak when several workers and shoppers came down with the mysterious flu-like virus. However, concerns began to grow when it emerged that the Wuhan Institute of Virology – located just 8 miles away on the other side of the Yangtze River – was working extensively on bat coronaviruses at the time. Another key question was why only 50 patients out of the hundreds hospitalized with Covid in Wuhan had a direct connection to the market. One of the new studies, published in the journal Science, used mapping tools to calculate the longitude and latitude locations of 156 of those initial cases. Virologist Shi Zheng-li works with her colleague in the P4 lab of the Wuhan Institute of Virology in Hubei province – which is at the heart of the lab leak theory. Nicknamed the ‘Bat Lady’, Zheng-li hunted down dozens of deadly Covid-19 viruses in bat caves and studied them at the WIV Photo: The Wuhan Institute of Virology, where critical data was wiped out by Chinese scientists The highest density of December cases was found within a 3-mile (5km) radius around the market – a relatively tiny spot in a sprawling city of 11 million people about the size of London. Earlier in the pandemic, many were surprised that the cases were not even more closely related. However, the researchers behind the new study said it was consistent with how Covid is transmitted – mainly by people with mild illness who travel and spread it to others.
China’s official pandemic timeline for the coronavirus pandemic and the factors undermining it
Official schedule
December 8, 2019 – The first date China has acknowledged infection
December 31 – China reports “pneumonia of unknown cause” to the World Health Organization for the first time
January 1, 2020 – Wuhan seafood market closed for disinfection
January 7 – President Xi Jinping discusses the coronavirus outbreak with his Politburo
January 9 – China releases the genome of the coronavirus
January 11 – China reports its first death
January 13 – The first case outside of China is confirmed
January 20 – China’s National Health Commission confirms human-to-human transmission
January 23 – Wuhan is locked down
January 31 – WHO declares ‘outbreak of international concern’ as China admits thousands of cases
February 23 – Italy reports a cluster of cases in the first major outbreak in the West
May 29 – China claims the virus did not originate from wet markets but from Chinese bats before jumping to humans via an “intermediate animal”
July 31 – Chinese researcher admits some coronavirus experiments were conducted in less biosecure labs
December 16 – WHO announces it will travel to Wuhan to investigate the origin of the virus in January
January 5, 2021 – China refuses entry to WHO research team
February 9 – WHO rejects theory virus leaked from lab – supports China’s claim it was imported from frozen meat
March 28 – Former US national security officials say intelligence shows ‘there was a direct order from Beijing to destroy all virus samples’ at Wuhan lab
New elements
2012: Six miners were struck down with a mysterious flu-like illness in Mojiang Cave in Yunnan.
They were found to be infected by the closest known relative of Covid, which shares 97% of its genes.
RATG13 samples are sent to the Wuhan Institute of Virology for study.
September 2019 – Blood samples taken in a lung cancer screening test in Italy later test positive for coronavirus
October – Whistleblower Wei Jingsheng claims China deliberately spread Covid at the World Military Games in Wuhan in October, two months before the rest of the world knew about the virus
October – Xi Jinping’s authoritarian regime tried desperately to shut down whistleblowers like Mr Jingsheng. Any social media reports of a new SARS virus or “outbreak” were censored
October-December – Increase in ‘flu and pneumonia’ cases in northern Italy that could be linked to coronavirus
November – Whistleblower Mr Jingsheng claims he took his concerns about military matches to senior Trump administration officials but was ignored
November – An intelligence report passed to agencies in Washington states that three staff members at the Wuhan Institute of Virology sought hospital care in November 2019 after developing symptoms consistent with Covid
November – Sewage samples taken in Florianópolis, Brazil suggest a virus was present
November 10 – Milan woman undergoes a skin biopsy, providing a sample that later shows signs of the virus
November 17 – Leaked documents show a case was detected in China on this date
December – Doctors in China, including Li Wenliang, report a new type of respiratory infection. But Chinese police detained him and eight of his colleagues for questioning – instead of releasing reports and warning the public
December 1 – Chinese researchers report an infection on this date in a peer-reviewed study, but it has not been acknowledged by Beijing
December 18 – Sewage samples taken in Milan and Turin suggest the virus was circulating in the cities
December 26 – Samples analyzed showed that a new type of SARS was circulating as early as December 26, but Wuhan was not locked down until January 22
Jan 2020 – Barcelona sewage samples suggest virus was in the city
January 3 – Covid-19 infections begin to sweep into other nations, including the US, as the WHO declares the outbreak a public health emergency of international concern
May – Scientists at a government lab in California conclude that Covid-19 may have escaped from a facility in Wuhan
July – WHO chief Tedros Adhanom Ghebreyesus said China failed to share vital raw data during its Wuhan investigation. China rejected these claims
June 2021: Top US virus expert Dr Anthony Fauci warned Covid may have been made in a lab, publicly released emails reveal.
August: The world’s first Covid-19 patient may have been infected by a bat while working in a lab in Wuhan, China, WHO chief Dr Peter Embarek said
August: A damning report by Republicans in the US claims the coronavirus leaked from the Wuhan Institute of Virology, shortly after the facility tried to improve its air safety and waste treatment systems
The report also cited “ample evidence” that laboratory scientists were working to modify coronaviruses to infect humans and that such manipulation could be concealed.
October: A US intelligence review into the origins of the pandemic does not reach a verdict on whether the virus emerged through animal-to-human transmission or a laboratory leak.
Chinese officials called the report “political and false”.
January 2022: Leaked emails from leading British scientist Sir Jeremy Farrar show he admitted in February 2020 that it was a “possible explanation” that the virus could be man-made. But he went on to call the theory a “conspiracy”.
February: Sir Farrar is called to be interviewed under oath by the US Congress. Officials want him to explain why he moved away from the lab leak theory.
There was no widespread testing at the time, which meant that the only people who were officially diagnosed were those who were very ill in hospital.
The research found that a large proportion of the early patients were people who lived in the surrounding neighborhood but had no direct connection to the market.
Professor Robertson told the BBC: “Knowing what we know about the virus now, it’s exactly what we would expect – because a lot of people get very mildly ill, so they would be out in the community passing the virus on to others and the severe cases would be hard to link between them”.
The researchers conducted tests that showed it was highly unlikely that such a pattern would occur just from…
