Dr Anthony Fauci, a former top United States public health official, has declined to answer questions at a Republican-led Senate committee hearing into the origins of COVID-19 and the handling of the pandemic.The former director of the National Institute of Allergy and Infectious Diseases (NIAID) repeatedly invoked his Fifth Amendment right against self-incrimination on Wednesday.Recommended Stories list of 1 itemlist 1 of 1Fauci invokes Fifth Amendment in heated COVID-19 Senate hearingend of listFauci was called to testify by Republican Senator Rand Paul of Kentucky, who accuses him of misleading Congress and questions whether US-funded research in China played a role in the pandemic, allegations Fauci denies.Although former President Joe Biden granted Fauci a preemptive pardon in 2025, Republicans claim it does not protect him from any alleged crimes committed after it was issued, such as perjuring himself at a Senate hearing.Fauci’s lawyers advised him not to testify, arguing that anything he said under oath could expose him to new legal risks.Here is what to know:Who is Anthony Fauci?Fauci, 85, is a physician and immunologist who led the US NIAID for 38 years, advising seven presidents, both Republican and Democratic.He became the public face of the US response to the COVID-19 pandemic in 2020, after helping lead the country’s response to health crises including HIV/AIDS, Ebola and the 2001 anthrax attacks.He became a target of conservative criticism over pandemic policies, including mask recommendations, vaccines and school closures.During his last year in government, Fauci was also chief medical adviser to Biden until he retired in 2022.During the pandemic, between 2019 and 2022, he kept more than 1,000 pages of diary entries documenting his work advising the White House and responding to the pandemic.The notes chronicle his interactions with senior officials and the media.Why is Fauci being questioned?He was subpoenaed to testify over his handling of the pandemic and its origins before the Senate Homeland Security and Governmental Affairs Committee.The hearing, led by Paul, focused on several issues: