Anthony Fauci, the former long-serving director of the National Institute of Allergy and Infectious Diseases (Niaid) who served as a key adviser to Donald Trump and Joe Biden during the Covid-19 pandemic, is due to appear on Wednesday at a high-profile US Senate hearing. Senators are expected to question Fauci about whether the Covid-19 virus began as a “lab leak”, a claim virologists have argued is unlikely.
The testimony is part of a longtime Republican investigation into the origins of the pandemic, led by Senator Rand Paul of Kentucky. While Republicans have characterized their work as investigating “the origins of Covid-19 and risky taxpayer-funded life science research”, scientists have described Paul’s investigation as “vilification and harassment” of Fauci, who led Niaid for 38 years before retiring.
What is Rand Paul arguing?
Paul, who chairs the Senate committee on homeland security and governmental affairs, said last week:
“For years, Americans were told a lab origin wasn’t just unlikely – it was dismissed outright by the very people funding and reviewing this research,”The hearing will take place in the committee where Fauci is scheduled to testify, and it comes amid renewed Republican focus on the lab leak theory.
Who is Anthony Fauci and why does this matter?
Fauci is 85 and served under seven US presidents through numerous health crises, including the HIV crisis, Ebola outbreaks and the first coronavirus outbreak, called. He became a household name overnight when the Covid-19 pandemic halted social life in 2020. His role in guiding the federal response has made him one of the most prominent and polarizing public health figures of the pandemic era.
The “lab leak” theory has since gained significant traction in Republican circles. In just one example, the White House published a on the theory in April 2025 that served as a rationale for defunding the National Institutes of Health (NIH).
What do scientists say about the pandemic’s origins?
A 2024 survey of virologists from the found that most believed the pandemic began as a so-called spillover event, or a virus jumping from an infected animal to a human. Similarly, a group of virologists argued in the that the “preponderance” of evidence points to a spillover, even as the “lab leak” theory received outsized attention.
The hearing comes just days after Paul released what he described as Fauci’s “diary”, a more than 1,100-page document characterized as revealing Fauci’s inner conflicts about the lab leak theory. this is a normal part of reaching scientific opinion.
The diary also contained , who he advised closely during the early days of the pandemic. He described the president as “rambling”, “crazy”, “desperate”, “bumbling”, “incompetent”, “an idiot”, “a true embarrassment”, “totally nuts” and “truly an obnoxious adolescent”.
Key Facts
- Anthony Fauci is due to testify on Wednesday at a US Senate hearing.
- The hearing is part of a Republican investigation led by Senator Rand Paul into Covid-19 origins.
- Senators are expected to question Fauci about the lab leak theory.
- Fauci led Niaid for 38 years before retiring.
- Paul released what he described as Fauci’s “diary” just days before the hearing.
