More than 20 million deaths and a historic economic shock: the origin of SARS-CoV-2, the virus responsible for Covid-19, continues to fuel debate and controversy. International experts are today publishing a highly anticipated scientific update.
23 international experts have decided. Their analysis appeared in the journal Nature, one of the most recognized scientific publications in the world. These former experts commissioned by the World Health Organization (WHO) consider it the most solid scenario to explain the appearance of the Covid virus at the end of 2019 in Wuhan in China. So laboratory accident? Animal cause?
The signatories were part of the SAGO group, created by the World Health Organization to shed light on the origin of SARS-CoV-2 and guide future investigations of new pathogens. After three and a half years of work, examination of scientific literature and international discussions, they provide a clear synthesis and specify, however, that they are speaking in their own name and not officially in the name of the WHO. Their objective, they write, is to place the debate on a scientific ground, while the question remains highly politicized.
Experts examined the famous hypothesis of a laboratory accident. Their position is nuanced: no concrete proof of a security breach has been provided to date. However, they acknowledge that they did not have access to certain information that they considered necessary, in particular detailed audits of safety conditions in the laboratories. Due to the lack of complete information, this hypothesis cannot be definitively excluded, but it is not supported by direct scientific evidence. As for the idea of voluntary genetic manipulation, it is considered unlikely in view of the analyzes of the genome, compatible with natural mechanisms already observed in other coronaviruses.
Ultimately, the evidence published to date mainly favors a zoonotic origin, that is to say a passage of the virus from animals to humans. For experts, animals infected with SARS-CoV-2 transmitted the virus to humans. This is how the pandemic started according to scientific evidence. “Most peer-reviewed scientific evidence supports this hypothesis” they recall. Coronaviruses very similar to SARS-CoV-2 have been identified in Southeast Asian bats, with up to 96.8% genetic similarity. This does not mean that it is the direct “parent” virus, but confirms the existence of a natural reservoir (i.e. animals in which related viruses were already circulating) and the circulation of related viruses in wildlife before the pandemic.
The Huanan market, in Wuhan, also appears central in the initial phase: more than 60% of the first cases recorded in December 2019 were linked there. Environmental samples found viral material near stalls where live animals susceptible to coronaviruses, such as raccoon dogs or certain species of rodents, were sold. Two distinct genetic lineages were also identified very early, which suggests an already active circulation before the official detection of the first cases. “We also know that the Huanan Seafood Market in Wuhan played an important role in the early transmission and initial spread of the virus.”
For the authors, the issue is not to name someone responsible, but to understand in order to better prevent future pandemics. They call on researchers and governments to make data useful for independent evaluation accessible. Because beyond the debate, the impact remains colossal: according to their estimates, the pandemic has caused more than 20 million deaths – a toll reached at the end of 2022 – and cost the global economy up to $16,000 billion.
