Alina Chan: The German intelligence report gives 'the lab leak hypothesis a big boost in credibility'

According to a recently published report, the German Federal Intelligence Service assumes with a probability of 80 to 95 percent that COVID-19 originated from a laboratory. You argued for the lab leak hypothesis already years ago in your book "Viral: The Search for the Origin of COVID-19" and called the outbreak potentially the "most costly accident in the history of science." Do you expect the public stance to change now through reports like that, or will the idea that the lab theory is a conspiracy theory persist?

Alina Chan : Polls conducted in the US and other countries in the past five years have shown that a significant percentage of people believe COVID-19 originated in a laboratory. For example, 7 in 10 Americans polled by Deseret News/HarrisX in 2024 think COVID-19 came from a lab. The news that scientists in German intelligence and US intelligence favor a lab origin will give the lab leak hypothesis a big boost in credibility. I barely know any people who seriously still think of the lab leak hypothesis as a conspiracy theory.

Can you briefly explain why you suspect that the origin of COVID-19 might be linked to a laboratory in Wuhan?

I laid out the case for a laboratory origin of Covid-19 in a New York Times opinion piece last year. In 2018, the scientists in Wuhan and their US collaborators said they would create SARS-like viruses with a very unique feature. In 2019, exactly such a virus appeared in their city and was causing an outbreak. We also know that the Wuhan scientists were working with these viruses at low biosafety. In parallel, despite multiple groups of investigators looking for the animal source of COVID-19 across China and over the past five years, no one has reported finding any infected animals.

Most experts agree that the virus detected in Wuhan in 2019 was already well adapted for transmitting in humans and other animals. Yet there is zero trace of its roughly 1000-kilometer journey from its ancestral origins in South China/Southeast Asia to Wuhan in Central China. Given this incredible coincidence of both time and place, the lab leak hypothesis is far more likely than a natural origin of the virus via the Wuhan market.

What do you mean by "well adapted for transmitting in humans"?

In the case of SARS and MERS, other coronaviruses that emerged in humans in the 21st century, experts observed that the viruses were adapting to get better at spreading among humans. With SARS-CoV-2, there was no such clear adaptation phase. It was highly transmissible from the start. Given the absence of any trace of the virus in the wildlife trade or fur farms, we must seriously consider the fact that the virus may have adapted for infecting human cells while being studied in a laboratory. Before the pandemic, experts were already warning of such dangers.

What role does the Wuhan Institute of Virology play in this hypothesis?

The WIV was trying to understand how diverse coronaviruses in nature might jump across species and potentially cause human outbreaks. They likely had the largest collection of novel SARS-like coronaviruses and were studying these at low biosafety, BSL-2, a level that cannot protect against the leak of such airborne respiratory viruses. Their experiments included serially passaging these viruses in cells from different species, including primate and human cells. They also synthesized and genetically modified such viruses. In 2018, their US collaborator suggested inserting furin cleavage sites into novel SARS-like viruses at the S1/S2 junction of the spike. We do not know of any other lab around the world that planned to do this. In 2019, a novel SARS-like virus with a novel furin cleavage site was causing the Covid-19 outbreak in Wuhan. Out of hundreds of SARS-like viruses discovered to date, only the COVID-19 virus has a furin cleavage site at the spike S1/S2 junction.

Why do you doubt that the pandemic originated from a seafood market in Wuhan? Isn't that much as likely?

The available genetic and epidemiological data convincingly show that the virus only caused the detected outbreak at the market after it had been circulating in Wuhan. Some of the first recorded cases had no connection to the market. But beyond that, we also know that the Chinese authorities ordered patient samples to be destroyed on January 3, 2020, and that investigators who had assumed a repeat of the 2003 SARS epidemic were only searching for cases linked to the market or living near the market. This means that most of the earliest cases were missed, and the available data tells us nothing about how the pandemic started.

One alarming detail — leaked to The Wall Street Journal and confirmed by current and former US government officials — is that scientists on Dr. Shi ' s team, which had collected and worked on viruses closely related to SARS-CoV-2, fell ill with Covid-like symptoms in the fall of 2019. Additionally, no direct animal source has been identified at the market that could have transmitted the virus to humans. This further weakens the argument for a natural spillover event occurring at the market.

Are there any direct genetic clues that point to a lab origin?

One controversial point is the presence of the furin cleavage site in SARS-CoV-2, which enhances the virus ' s ability to infect human cells. This feature is not found in any of the hundreds of other known SARS-related coronaviruses. It could have emerged through natural evolution, but the Wuhan scientists said in 2018 that they wanted to genetically insert furin cleavage sites into SARS-like viruses in a lab. It is as if the scientists said they wanted to put horns on horses. And the very next year, a unicorn is rampaging through their city.

Why do you think there has been so much resistance to investigating the lab leak hypothesis?

Acknowledging a lab leak would have serious geopolitical consequences, particularly for China. Additionally, the scientific community, including organizations that advocated for or funded virus research in Wuhan, may be hesitant to fully explore this possibility because they may be blamed for the pandemic. In February 2020, one well-known virologist said that a lab origin of COVID-19 would indict the field of virology.

Is the case now closed for you?

Until we have full transparency and access to all relevant data, we cannot rule out any hypothesis. However, the available evidence very strongly points to an accidental lab leak origin of Covid-19. We must take decisive action internationally to prevent future catastrophic lab accidents.

What would be needed to determine the true origin of SARS-CoV-2?

China needs to grant independent investigators access to WIV records, including lab notebooks, virus databases, and personnel health records. The Chinese authorities should also share the full data and methodology they have from searching for the natural origin of COVID-19. However, I do not see this as likely in the near future, so investigators must make their assessments using what is available and continue to pursue routes of inquiry outside of China - for instance, more thoroughly obtaining and examining communications between Wuhan scientists and their international collaborators.

How can we prevent future lab-based pandemics, regardless of COVID-19's origin?

We need stricter and independent oversight of high-risk pathogen research. In addition, I believe a key bottleneck is visibility into the wide range of research activities around the world that pose pandemic risks. There should be more efforts to track and better regulate such research.

Dr. Alina Chan is a molecular biologist at the Broad Institute of MIT and Harvard and co-author of "Viral: The Search for the Origin of Covid-19".