Early on in the pandemic, there was a lot of talk about whether the virus that causes COVID-19 could have leaked from a lab in Wuhan, China. Some scientists and politicians circulated this idea, but there was no substantiated evidence to back it up.
The most likely story is that the virus crossed over from animals, probably bats, into an intermediary species, before making the jump to humans. That’s how SARS and MERS ended up in humans: we got SARS from palm civets, and MERS from camels.
That said, we still don’t know where COVID-19 came from. We have some evidence to support the natural spillover idea. For example, most of the people in Wuhan who had Covid-like symptoms in December of 2019 were exposed to animals before they got sick. But, we still haven’t found a bat or pangolin in the wild that has COVID-19. We have no smoking gun, if you will.
In the absence of that proof, some people think something else must have…