Transmission of the COVID-19 virus from bats to humans through another animal is the most likely scenario. AP reported referring to a joint study by the WHO and China.

It is noted that the leak of the virus from the laboratory is extremely unlikely. 

The findings provide no new insight into how the virus first appeared and leave many questions unanswered, although this is to be expected. But the report provides more details on the reasons behind the researchers' conclusions. The team proposed further research in all areas other than the laboratory leak hypothesis.

The report, which is expected to be released on March 30, is under close scrutiny as pinpointing the origin of the virus could help scientists prevent future pandemics.

The report is based on a visit by a group of international WHO experts to Wuhan, where COVID-19 was first detected.

Researchers have listed four scenarios for the COVID-19 origin. The first place on the list was taken by transmission from bats through another animal, which, according to them, is very likely. They assessed direct spread from bats to humans as likely and stated that spread through food in the cold chain is possible but unlikely.

The draft report does not provide definitive conclusions on whether the outbreak in the Wuhan seafood market has begun or not.

Finding other cases of the disease before the outbreak in the market suggests that it may have started elsewhere. But the report notes that there could have been milder cases that went unnoticed.

The report says the cold chain is known to be the driving force behind the long-range spread of the virus, but it has been questioned if it could trigger an outbreak - the risk is lower than with a person-to-person respiratory infection, and most experts agree.

The report cites several reasons why the possibility of a virus leaking from a laboratory in Wuhan is hardly considered. Such laboratory accidents are rare, and laboratories in Wuhan working on coronaviruses and vaccines are well managed, the report said. Until December 2019, no laboratory had registered viruses closely related to SARS-CoV-2.