The problem for the lab-leak position is that the U.S. has never had access to the Wuhan lab and has thus been unable to reach a definitive answer for more than five years. Now that the CIA has at last come to a conclusion, not all scientists are sold on what it has reported, seeing the results as thinly scientifically sourced.

Langley joins the FBI and Energy Department in agreeing that a lab leak is the most likely source of the pandemic.

It was unclear the extent to which the agency has collected new intelligence on COVID-19's origins and whether that new evidence was used to formulate the latest assessment.