Question: where did covid-19 come from

Zoe Vance answered on 18 Mar 2025:

We’re fairly sure now that the virus causing covid-19 came from a wild animal or animals being sold at a market in Wuhan in China. It might have been a raccoon dog but it’s hard to be very confident of that. All of the early cases of the disease centre around the market and when researchers looked at swabs from the market they found that there was a lot of genetic material from the virus at one specific stall which is where we think the animals were being sold. Selling live wild animals like this is quite risky because we don’t know what illnesses they might carry.

The viruses we’ve found in the wild that look most similar are in bats in Laos, a country near China, so we think that there are coronaviruses in wild animals in the area that can evolve to infect humans. Some kind of spread to other animals from the bats lead to humans being exposed and eventually to covid-19. This is called zoonosis, or zoonotic spillover if you wanted to know more about it, it’s quite a common way for new pathogens like viruses to get into humans, though not that many of them cause a pandemic like covid-19 did!