Dr. Anthony Fauci denied that the National Institutes of Health had funded gain-of-function research at the Wuhan lab U.S. intelligence is investigating as a possible origin of the COVID-19 pandemic during a testy exchange with Republican Sen. Rand Paul.

Officials from both the Trump and Biden administrations have said that the Chinese government worked for over a year to thwart an independent investigation into the origins of the virus, which has killed 3.3 million people worldwide, according to Johns Hopkins University, and both administrations cast doubt on the manner in which the WHO-China study was conducted in early 2021.