Islamabad: More than five years after the first cases of COVID-19 emerged in Wuhan, the origins of the virus that has claimed at least 20 million lives remain inconclusive, the World Health Organization said on Friday.
In a landmark report, the WHO’s Scientific Advisory Group for the Origins of Novel Pathogens (SAGO) said the weight of currently available scientific evidence still supports the theory that the virus likely spilled over from animals to humans.
However, the panel stressed that all hypotheses—including a lab-related incident—remain on the table due to a lack of critical data, particularly from China.
“Understanding how COVID-19 began is not just a scientific pursuit—it is a moral imperative to prevent future pandemics,” said SAGO Chair Dr. Marietjie Venter.
The group of 27 international scientists spent over three years reviewing peer-reviewed studies, unpublished research, intelligence assessments, and field investigations. But they concluded that the origin of SARS-CoV-2, the virus behind the COVID-19 pandemic, remains scientifically unresolved.
The SAGO report reiterates the need for greater transparency from countries, especially China, where the earliest known cases emerged in late 2019. The WHO has repeatedly requested access to raw data, including health records of laboratory staff, genetic sequences from early human cases, and full details of animals sold at Wuhan’s Huanan Seafood Market. These have not been provided.
“We continue to appeal to China and any other country with relevant information to share it openly,” said WHO Director-General Dr. Tedros Adhanom Ghebreyesus.
While the strongest evidence still suggests zoonotic spillover—likely from bats, possibly through an intermediate host—no direct precursor virus has been found in animals. In particular, raccoon dogs, palm civets, and other mammals sold at the Wuhan market remain under scrutiny.
Environmental samples from the market tested positive for SARS-CoV-2, with genetic traces of susceptible animal species detected, but all live animal samples collected later tested negative.
Conversely, the theory that the virus may have accidentally escaped from a laboratory—such as the Wuhan Institute of Virology—could not be ruled out due to missing records and lack of cooperation.
“There’s simply not enough information to confirm or dismiss a lab-related incident,” the report states. The group also dismissed theories about virus manipulation or cold-chain importation due to lack of credible supporting evidence.
The panel said multiple spillover events may have occurred, noting the presence of distinct SARS-CoV-2 lineages in early 2019 cases. However, determining when, where, and how humans were first infected remains impossible without further cooperation and data sharing.
The report follows 52 formal meetings of SAGO since its creation in 2021 and is based on its evaluation of new studies, interviews, and expert briefings. Its conclusions underscore the difficulty of tracing the origins of emerging pathogens without open access to early clinical data, biosafety records, and upstream animal trade routes.
SAGO was tasked by WHO not only to determine the origins of COVID-19 but to develop a global framework for investigating future pandemics. While that framework has now been published, the investigation into COVID-19’s origins remains open-ended.
“The work is not done,” said Dr. Tedros. “We welcome any further evidence that may emerge. The world deserves answers—not just for the past, but to prepare for the future.”
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