Why is Dr Fauci testifying? Ex White House medical advisor invokes Fifth Amendment as Rand Paul grills him at Senate hearing

Former White House medical adviser Anthony Fauci invoked his Fifth Amendment right against self-incrimination at a Senate hearing on Wednesday, refusing to answer questions as his long-running confrontation with Republican Senator Rand Paul escalated dramatically.

Fauci, who became one of the most recognisable figures in America during the COVID-19 pandemic, appeared before the Senate Homeland Security and Governmental Affairs Committee, chaired by Paul. The Kentucky senator has repeatedly accused Fauci of misleading Congress over U.S.-funded research connected to the Wuhan Institute of Virology and has publicly called for his prosecution.

“Under the advice of my attorneys, I will invoke my right under the 5th Amendment of the Constitution to refrain from answering your questions,” Fauci said in his opening statement.


Fauci maintained that he has testified truthfully before Congress and rejected allegations that he misrepresented the nature of research supported by the National Institutes of Health.

Why did Anthony Fauci invoke the Fifth Amendment?

Fauci said his decision was driven by Paul’s years-long push to have him prosecuted, arguing that the hearing could be used to build a criminal case against him.

He pointed to the senator’s repeated statements about putting him “behind bars” as well as Paul’s recent release of more than 1,000 pages of Fauci’s pandemic-era diary entries.

“Given Senator Paul’s obvious obsession with calling for my prosecution, his repeated slanderous comments about me, and recently his publicly releasing my unredacted personal diary aimed at embarrassing and intimidating me,” Fauci said, he believed the hearing was intended to get him to make statements that could support Paul’s calls for prosecution.

“Any reasonable person who has followed his unhinged obsession with me would readily come to the same conclusion,” he added.

Fauci spent 38 years leading the National Institute of Allergy and Infectious Diseases and became a central figure in the U.S. government’s response to COVID-19.

Rand Paul and Fauci clash again over Wuhan research

At the centre of the dispute is the contentious question of whether NIH funding supported “gain-of-function” research in Wuhan, China.

Broadly, gain-of-function experiments can involve altering pathogens in ways that change their characteristics, potentially including their transmissibility or severity. However, exactly which experiments qualify under that label has been the subject of scientific and regulatory debate.

Paul contends that NIH money supported research in Wuhan that should be considered gain-of-function and has accused Fauci of lying when he told Congress otherwise.

Fauci has consistently rejected that allegation. His position is that the research in question did not fall under the U.S. government’s applicable regulatory definition of gain-of-function research.

The disagreement has fuelled years of bitter exchanges between the two men, including several confrontational congressional appearances during and after the pandemic.

Fauci’s lawyer calls Paul’s campaign an ‘obsessive vendetta’

Fauci’s attorney, David Schertler, sharply attacked Paul’s pursuit of his client, describing it as “an obsessive vendetta.”

Schertler said the allegations against Fauci were “false and disgraceful” and indicated that Fauci’s legal team would consider its options for holding Paul accountable.

According to Schertler, a heated 2021 exchange between the senator and Fauci marked the beginning of what he described as “an intense and seemingly pathological course of retribution, revenge, and obsession.”

Paul, meanwhile, has shown no indication of backing away from his allegations.

What is in Anthony Fauci’s pandemic diary?

The latest confrontation comes after Paul released 1,141 pages of Fauci’s diary entries covering the period from December 2019 through December 2022.

Paul claimed the records undermine aspects of the public account given by Fauci and other health officials during the pandemic.

“Many entries in Fauci’s daily historical account completely undermine the official narrative that Fauci and other public health officials espoused,” Paul said.

A fact-check document supplied by a Fauci representative disputed that interpretation, saying his private entries were consistent with positions he expressed publicly at the time.

The diaries largely document Fauci’s meetings, media appearances and experiences as his profile soared during the pandemic.

Fauci has said publicly since 2021 that he remained open to the possibility that COVID-19 originated in a laboratory. He also spoke during the early stages of the pandemic about issues including asymptomatic transmission and concerns over China’s transparency.

What do US agencies say about the origins of COVID-19?

The precise origins of SARS-CoV-2 remain unsettled, with U.S. intelligence agencies reaching differing assessments about whether the virus emerged naturally or resulted from a laboratory-related incident.

The FBI said in 2023 that it assessed a laboratory incident in Wuhan was likely responsible for the pandemic.

The CIA shifted its assessment in January 2025 toward a lab-related origin being more likely, but attached “low confidence” to that conclusion.

Other elements of the U.S. intelligence community have favoured natural transmission, underscoring the continuing uncertainty surrounding one of the most fiercely debated questions to emerge from the pandemic.

China has repeatedly rejected allegations that COVID-19 originated from a laboratory leak.

RFK Jr says he gave Fauci files to Rand Paul

U.S. Health Secretary Robert F. Kennedy Jr., another prominent Fauci critic, said on Fox News that he provided the files to Paul after they were discovered on government servers.

Both Kennedy and Paul have suggested that Fauci could face potential legal exposure if his latest testimony conflicted with previous statements to Congress.

The issue is complicated by a preemptive pardon granted to Fauci by former President Joe Biden in January 2025. Biden said at the time that the move was intended to protect Fauci from what he characterised as potentially “unjustified and politically motivated prosecutions.”

The pardon did not amount to an admission that Fauci had committed wrongdoing.

Gain-of-function research returns to political spotlight

The hearing comes as Washington again focuses on research involving potentially dangerous pathogens.

The Trump administration announced a policy on Tuesday barring federal funding for research it classifies as “dangerous gain-of-function” work, bringing renewed attention to the same category of experiments at the centre of the Fauci-Paul dispute.

Separately, David Morens, a former Fauci adviser, was indicted in April on charges related to the alleged concealment of federal records concerning research grants and investigations into the origins of COVID-19.

Fauci was not charged in that case.

Wednesday’s hearing nevertheless demonstrated that, years after the height of the pandemic, the political battle over Fauci, Wuhan research and the origins of COVID-19 remains far from over.