The Central Intelligence Agency said Saturday that it’s more likely a lab leak caused the Covid-19 pandemic than an infected animal that spread the virus to people, changing the agency’s yearslong stance that it couldn’t conclude with certainty where the pandemic started.

The CIA now assesses the virus that causes Covid-19 more likely originated from an accidental lab leak in China, rather than occurring naturally, according to a statement from the agency Saturday, just days after Director John Ratcliffe took the reins.

The Central Intelligence Agency said the Covid-19 pandemic “more likely” originated from a lab leak than a natural source, shifting its stance after previously saying both scenarios were possible.