Investigations Into The Origin Of COVID-19

There are several ongoing efforts by scientists, governments, international organisations, and others to determine the origin of SARS-CoV-2, the virus responsible for the COVID-19 pandemic. Most scientists say that as with other pandemics in human history, the virus is likely of zoonotic origin in a natural setting, and ultimately originated from a bat-borne virus. Many other explanations, including several conspiracy theories, have been proposed about the origins of the virus. Some scientists and politicians have speculated that SARS-CoV-2 was accidentally released from a laboratory, but this theory is considered much less likely than a natural origin due to the absence of supporting evidence.

SARS-CoV-2 has close genetic similarity to multiple previously identified bat coronaviruses, suggesting it crossed over into humans from bats. Research is ongoing as to whether SARS-CoV-2 came directly from bats or indirectly through any intermediate hosts. Initial genome sequences of the virus showed little genetic diversity, although subsequently a number of stable variants emerged (some spreading more vigorously), indicating that the spillover event introducing SARS-CoV-2 to humans is likely to have occurred in late 2019. Health authorities and scientists internationally state that as with the 2002–2004 outbreak of SARS-1, efforts to trace the specific geographic and taxonomic origins of SARS-CoV-2 could take years, and the results could be inconclusive.

In January 2021, the World Health Assembly (decision-making body of the World Health Organization (WHO)) commissioned a study on the origins of the virus, to be conducted jointly between WHO experts and Chinese scientists. In March 2021, the findings of this study were published online in a report to the WHO Commissioner-General. Echoing the assessment of most virologists, the report determined that the virus most likely had a zoonotic origin in bats, possibly transmitted through an intermediate host. It also stated that a laboratory origin for the virus was "extremely unlikely".

Scientists found the conclusions of the WHO report to be helpful but noted that more work was needed. In the United States, the European Union, and other countries, some criticised the lack of transparency and data access in the report's formulation. The WHO issued its 30 March report alongside a statement of the WHO director-general Tedros Adhanom Ghebreyesus saying that the matter "requires further investigation". The U.S. government and 13 other countries and the EU issued statements on the same day, echoing Tedros's critique of the report for lacking transparency and data access in its formulation. In a later press conference, the WHO director-general said it was "premature" for the WHO's report to rule out a potential link between a laboratory leak and called on China to provide 'raw data' and lab audits in a second phase of investigations. On 12 October 2021, the WHO announced a new team to study the origins of the COVID-19 pandemic. In June 2022, this team released an additional report advocating for more investigations in the various possible pathways of emergence, including the possibility of a lab leak.

Earlier, on 22 July 2021, the Chinese government had held a press conference in which Zeng Yixin, Vice Health Minister of the National Health Commission (NHC), said that China would not participate in a second phase of the WHO's investigation, denouncing it as "shocking" and "arrogant". In response to the WHO's June 2022 report, Chinese Foreign Ministry spokesperson Zhao Lijian called the lab leak theory "a lie concocted by anti-China forces for political purposes, which has nothing to do with science".

Scientific background

COVID-19 is caused by infection with a virus called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). SARS-CoV-2 appears to have originated in bats and to have spread to humans by zoonotic transfer. Its exact evolutionary history, the identity and provenance of its most recent ancestors, and the place, time, and mechanism of transmission of the first human infection, remain unknown. The biology and regional distribution of other coronaviruses in southeast Asia, including SARS-CoV, help scientists understand more about the origins of SARS-CoV-2.

Taxonomically, SARS-CoV-2 is a virus of the species ''severe acute respiratory syndrome–related coronavirus'' (SARSr-CoV). It is believed to have zoonotic origins and has close genetic similarity to bat coronaviruses, suggesting it emerged from a bat-borne virus. Research is ongoing as to whether SARS-CoV-2 came directly from bats or indirectly through any intermediate hosts. The virus shows little genetic diversity, indicating that the spillover event introducing SARS-CoV-2 to humans is likely to have occurred in late 2019. Ultimately, the specific evolutionary history of SARS-CoV-2 in relation to other coronaviruses will be critical to understanding how, where and when the virus spilled over into a human population.

Reservoir and origin

Available scientific evidence suggests that SARS-CoV-2 has a natural zoonotic origin. Yet its origin, which remains unknown, has become debated within the context of global geopolitical tensions. Early in the pandemic, conspiracy theories spread on social media claiming that the virus was a biological weapon developed by China, amplified by echo chambers in the American far-right. Other conspiracy theories promoted misinformation that the virus is not communicable or was created to profit from new vaccines.

Some politicians and scientists have speculated that the virus may have accidentally leaked from the Wuhan Institute of Virology. This has led to calls in the media for further investigations into the matter. Many virologists who have studied coronaviruses consider the possibility very remote. The WHO-convened Global Study of the Origins of SARS-CoV-2 from March 2021 stated that such an explanation is extremely unlikely. In an interview on 12 August 2021, Peter Ben Embarek, the chief investigator of the WHO team, told a Danish TV documentary that the WHO team felt pressured from Chinese scientists to put "extremely unlikely" as their assessment.

A 2021 study found possible links between climate change and transmission of COVID-19 by bats. The authors found that climate-driven changes in the distribution and richness of bat species harboring coronaviruses may have occurred leading to a concentration of such species in eastern Asian hotspots (southern China, Myanmar and Laos). Tell conditions favors transmission of viruses. In this area live pangolins that are sold among other in the Wuhan wet market and are suspected of being the intermediate host in the transmission of SARS-CoV-2 who cause the pandemic. The study was cited at 22 other studies in the National Library of Medicine of the USA. Before World Health Day