An international team of scientists has spent months preparing for a mission to Wuhan to search for the origins of the coronavirus pandemic. Their first challenge: actually getting into China.

For almost a year, the World Health Organization has been working with Chinese authorities to secure access to the epicenter of the initial outbreak. Terms of reference were drawn up. The team was selected. They expected to arrive in China just after the new year.

By New Year’s Eve, the WHO expert leading the mission did not have a flight booked. On Tuesday, WHO secretary general Tedros Adhanom Ghebreyesus expressed “disappointment” that China had yet to finalize permissions for the trip – his most pointed criticism of China to date. China has said the two sides are “still negotiating” arrangements for the trip.

The delay and the rare rebuke point to the many challenges facing the WHO team tasked with investigating one of the most complex and critical questions of our time. It is a question that has become increasingly politically fraught as the United States and other critics blame China for the pandemic that has now claimed more than 1.8 million lives.

Beijing for months had rejected calls for a probe into the origins of the virus, later agreeing to a WHO-led investigation only if it were not country-specific. Chinese officials have pushed theories that the virus came from outside the country while controlling related research and blocking domestic scientists from publishing independent studies into the causes of the outbreak.

“With the amount of division and polarization that’s already occurred this [past] year, it’s going to be really hard to get objective, honest answers,” said Raina MacIntyre, professor of biosecurity at the University of New South Wales, in Australia.


The scientists are not only undertaking the mission in the middle of a geopolitical standoff between China and the United States, in which the Trump administration has imposed new restrictions on Chinese tech companies and accused Beijing of obstructing the WHO investigation.

The team must go back in time, reconstructing events that happened before most people knew anything was amiss. That would have been challenging even last winter. The delay may make it difficult or impossible to reach definitive conclusions.

“It has taken them an entire year to negotiate access in any meaningful way in China,” said Lawrence Gostin, a professor of global health at Georgetown University. “It’s like there was a murder and you go back to the crime scene a year later, after it was scrubbed, and you expect to find something.”

– – –

The scientists will start by revisiting the earliest coronavirus cases and reinterviewing people as they work backward, looking for clues, according to Peter Ben Embarek, a food safety expert and head of the mission.

They will try to reconstruct what happened at the Huanan Seafood Market in central Wuhan, initially linked to the outbreak, retracing everything that went in and out of that market in November and December 2019, Ben Embarek said, including products, animal and goods. From there, the team will “triangulate” the results, trying to determine a possible source.

Despite the delays and the politics, he remained hopeful they can make progress if they ever get to Wuhan. “It’s late, of course,” he said. “But it’s not too late.”


Ben Embarek said the most likely scenario was that the virus moved from a bat to an intermediate host, then to humans. Asked about two other theories – that the virus jumped directly from bats in Yunnan province to humans, or that it emerged from a Wuhan lab – he was skeptical, but said “everything is on the table.”

As for theories that the coronavirus was imported to China from elsewhere, Ben Embarek said this was “not the most likely hypothesis.” Still, he vowed to pursue all leads.

That could be tough. In China, the WHO’s visit is welcome in part because it is seen as an opportunity for vindication. Top officials have promoted fringe theories such as the transmission of the virus via imported frozen food, even as the country battles new clusters of cases linked to local weddings and funerals.

Chinese state media have seized on studies that found traces of the virus in Europe in mid-2019, pushing the idea that the virus did not originate in China.

“More and more evidence or research suggests that the pandemic was likely to have been caused by separate outbreaks in multiple places in the world,” Foreign Ministry spokeswoman Hua Chunying said on Monday, stressing that any origin-tracing should be “conducted worldwide.”

Observers say China is eager for the investigation to reflect well on its virus response, a constraint that may mean the scientists tiptoe around the most sensitive lines of inquiry.


“China of course would like to come off appearing confident and like it did the things it should do,” said Keiji Fukuda, director of the School of Public Health at the University of Hong Kong and former assistant director general for health security at the WHO.

“Whether this visit has been set up in a way to make it hard, or set up in a way that they will be able to give it a strong shot will come down to the terms of the mission and what access they get.”

But how much access the team will have is ultimately up to Beijing. The WHO can make recommendations and press for information, but it does not have the power to compel governments to hand over evidence.

The team’s plan to revisit the market, for instance, will only work if evidence from the market has been preserved. Asked if there were samples to study, Ben Embarek conceded that he did not know.

“I don’t know if there are still samples from that time available,” he said. “That is one of the issues we will look at.”

– – –

The team will face intense scrutiny from all sides. The WHO has been criticized for its handling of the initial outbreak in Wuhan and accused of deferring to Beijing.


It is clear now that Chinese officials waited days before informing the U.N. health agency about the outbreak of mysterious pneumonia in Wuhan, censoring reports of an alarming SARS-like virus.

Once the WHO was aware of the emerging threat, the agency amplified Chinese claims about case counts and transmissibility, lending credibility to statements that later proved false.

By late January, current and former WHO advisers were raising concerns about why the WHO was not signaling skepticism over China’s claims. Some also questioned the delay in declaring a public health emergency of international concern.

In February, the first WHO mission to China renewed questions about messaging. By that point, Chinese officials had admitted to problems with the initial response, but WHO experts kept heaping praise on China.

The agency’s defenders say the organization was being strategic, keeping Beijing on side and lines of communication open. But many felt their praise undermined WHO credibility when it needed it most.

“It’s not that China and Chinese leadership want praise, it’s that they don’t want criticism,” said Alexandra Phelan, a global health lawyer at Georgetown University’s Center for Global Health Science and Security.


Phelan noted that the scientists selected for the upcoming mission do not have a great deal of experience operating in China, where information is tightly controlled, and may not be well-equipped to navigate choppy political waters.

The WHO, said Yanzhong Huang, a senior fellow for global health at the Council on Foreign Relations, “needs more savvy diplomats.”

When the mission presents its findings, public health experts, foreign officials, and the public will again be parsing the WHO’s messaging for answers and any sign the information presented is not accurate or complete.

Tarik Jasarevic, a spokesman for the Geneva-based organization, said tracing the source of such an event “is a complex process.” It took time to link Middle East respiratory syndrome to dromedary camels, he noted, and to understand the bat origins of severe acute respiratory syndrome (SARS).

Wang Linfa, an expert in zoonotic diseases at the Duke-NUS Medical School in Singapore who helped identify bats as the natural hosts of the SARS virus, said this time would be different.

“The target is much more difficult this time because they don’t know where to start,” he said. “It’s much, much harder. The politics is ahead of the science now.”


Dale Fisher, an infectious diseases physician at National University Hospital in Singapore, who was on the WHO mission to China in February, was not optimistic the world would soon have answers.

“Unfortunately, it’s all going to be veiled in skepticism. It’s going to be impossible to prove that you’re being completely transparent,” he said.

“I don’t think people should expect to have an answer at the end of this trip.”

– – –

Kuo reported from Taipei, Taiwan.

Chinese officials note serious problems in coronavirus response. The World Health Organization keeps praising them.

Early missteps and state secrecy in China probably allowed the coronavirus to spread farther and faster

World Health Organization: China not sharing data on coronavirus infections among health-care workers