(CNN) Covid-19 probably came to people through an animal, and likely started spreading no more than a month or two before it was noticed in December of 2019, a World Health Organization draft report finds. The least likely source: a laboratory leak, the WHO's joint international team concluded. Possible but not probable is transmission from frozen or chilled food, and least likely is an accidental laboratory release, the report finds. Frozen food is also not a likely source, the report indicates. Plus, there is evidence the virus was circulating before the Huanan market outbreak -- including at other markets.

Source: CNN March 29, 2021 20:37 UTC