The former director of China’s Center for Disease Control and Protection (CDC) has said the lab leak theory for the origins of Covid-19 should not be discounted.
George Gao, an internationally respected virologist, also said another branch of the Chinese government had investigated the lab leak theory – the first such acknowledgment that some kind of official investigation took place. “They haven’t found wrongdoing,” he said.
Gao served as the CDC head until July 2022, putting him at the forefront of China’s investigations into the origins of Covid.
The virus was first detected in Wuhan, a city in central China, in December 2019. Numerous studies have suggested Covid most likely emerged from a wet market in Wuhan where live animals were sold.
However, the city is also home to the Wuhan Institute of Virology, a research facility that studies coronaviruses. That has led to the theory that the virus may have been leaked from a laboratory. The theory, initially dismissed by public health experts, was pushed by Donald Trump when he was US president. China has vigorously denied it.
Speaking to the BBC, Gao said: “You can always suspect anything. That’s science. Don’t rule out anything.”
Gao is now vice-president of the National Natural Science Foundation of China, a government funding body.
The investigation into the origins of Covid have been frustrated by the Chinese government’s lack of cooperation with international fact-finding efforts and the politicisation of the issue. In the west, questions about a possible lab leak have become linked to the idea that the virus was deliberately and maliciously released into the world, which has fuelled conspiracy theories.
But since Joe Biden became US president, authorities in the US have started to take the accidental leak theory more seriously. In May 2021 Biden ordered an intelligence investigation into the hypothesis. Earlier this year the Wall Street Journal reported that an updated and classified 2021 US energy department report had concluded with “low confidence” that the virus most likely emerged from a lab leak – a conclusion that runs counter to reports by a number of other US intelligence agencies.
In March 2021 a team of researchers from the World Health Organization (WHO) concluded, after a research visit to Wuhan, that the lab leak theory was “extremely unlikely”. But that visit had been hampered by the Chinese government and phase two of the investigation has since been abandoned. Speaking to Nature in February, Maria Van Kerkhove, a WHO epidemiologist, said: “The politics across the world of this really hampered progress on understanding the origins.”
The Chinese government has called the lab leak theory “false and erroneous”.
But in his BBC interview Gao said: “We really don’t know where the virus came from … the question is still open.”
James Wood, a professor of infectious diseases at the University of Cambridge, said: “Professor Gao is an internationally respected scientist. There is strong evidence from virus genomics that the Covid-19 virus was not artificially engineered, or made by humans, but likely arose from another virus infecting wildlife.
“Science deals in probabilities and not in certainties. In reality, it may never be possible to know with confidence how the Covid-19 virus entered the human population. What is important is that lessons are learned and that live wildlife trade, a well-recognised route for zoonotic virus transmission, is reduced or banned and that laboratory safety is properly regulated.”
Gao, who was educated in the UK, the US and Canada, is known in China’s public health community for having good relationships with international colleagues – and for being willing to occasionally speak out of turn with regard to the Communist party line.
In April 2021 Gao caused controversy by seemingly questioning the effectiveness of Chinese vaccines, although he later said he had been referring to all vaccines, not just Chinese ones.
China is grappling with a new wave of Covid infections after abandoning virtually all pandemic control restrictions in December, after three years of pursuing a zero-Covid policy. In May, Zhong Nanshan, a senior Chinese scientist, estimated that the peak of infections would arrive in late June, with about 65 million infections a week.
