In the United States, the debate over the origin of the COVID-19 virus is flaring up again.
A key figure who oversaw the COVID-19 response in the former Joe Biden administration recently made remarks lending weight to the "lab leak" theory as the origin of the virus. Meanwhile, Anthony Fauci, former director of the National Institute of Allergy and Infectious Diseases (NIAID), who led pandemic policy from the start of COVID-19, remained silent at a recent Senate hearing, invoking the right to remain silent more than 100 times. The divergent moves by former administration insiders who had supported the natural-origin theory are leaving considerable dents and doubts about the Biden administration's public health authority and transparency.
According to major media reports on the 2nd (local time), Ashish Jha, who served as White House COVID-19 response coordinator under Biden, appeared on CNN recently and said, "When I entered the White House, I viewed it as natural origin, but based on what I learned afterward, I have concluded that a lab leak is now more likely." Jha is a physician and public health scholar who served as dean of the Brown University School of Public Health. From April 2022 to June 2023, he was the White House COVID-19 response coordinator and led U.S. pandemic policy.
When the host asked a question to the effect that the current evidence supports the Wuhan lab leak theory, Jha agreed and explained that his assessment had changed. However, he did not specify what new classified information or scientific evidence he had confirmed, or why he changed his view. He ended the interview by saying, "In the United States, no one knows for sure (about the virus). The only people who know for sure are Chinese officials," adding, "We still need transparency and accountability on that."
The very next day, on the 3rd, Jha reiterated on X (formerly Twitter), "Based on the compelling circumstantial evidence I have seen, I believe a lab leak is far more likely. It was an accident, neither engineered nor intentional." He added, "Reasonable people can disagree while looking at the same evidence."
With the former White House pandemic chief acknowledging the possibility of a Wuhan lab leak in a public forum, the lab leak theory—long dismissed as a conspiracy theory—is being reappraised. The Wuhan Institute of Virology is China's top SARS research facility that has studied bat-borne coronaviruses. U.S. intelligence believes that in the fall of 2019, before the coronavirus spread, researchers at the institute fell ill with symptoms similar to COVID-19. U.S. intelligence agencies likewise reached assessments similar to Jha's based on that. The Central Intelligence Agency (CIA) assessed in early 2025 that the most likely scenario was that the coronavirus leaked from a lab at the Wuhan Institute of Virology, but rated the confidence as "low confidence." The Federal Bureau of Investigation (FBI) and the Department of Energy reached similar conclusions to the CIA.
Jha's remarks came four days after Fauci refused to answer questions about the origin of COVID-19 at a Senate hearing. On the 29th of last month, Fauci was summoned to a Senate Homeland Security and Governmental Affairs Committee hearing and effectively refused to answer, invoking the right to remain silent more than 100 times. The Fifth Amendment to the U.S. Constitution recognizes the right against self-incrimination, which protects a person from being compelled to testify in a way that could expose criminal liability. At the hearing, Fauci emphasized that this was an exercise of his right to avoid a perjury trap, saying, "The only reason this committee called me is to try to catch me saying something so they can send me to prison."
But Fauci had already been pardoned by former President Biden, sparking controversy. Senator Rand Paul, chair of the Senate Homeland Security and Governmental Affairs Committee who led the hearing, raised the question of whether someone who has been pardoned is eligible to invoke the Fifth Amendment. On Jan. 19, 2025, the day before he left office, Biden granted Fauci a "full and unconditional" preemptive pardon. According to Reuters, the scope of the pardon is so broad that it covers all potential federal crimes Fauci might have committed in connection with his duties over the 11 years from Jan. 1, 2014, to the day of the pardon in 2025. It was an unusual measure that preemptively exempted all potential federal offenses related to his duties without any specific crime having been established. By contrast, acts after Biden left office fall outside the scope of the pardon, so if Fauci's new statements at the hearing are deemed perjury, he would not be protected.
In particular, the pardon has been accompanied by an autopen controversy. An autopen is a device that replicates a president's signature. In October last year, the House Oversight Committee, led by Republicans, released a report stating that the documents for Fauci's preemptive pardon were signed with an autopen. Republicans are highlighting the moral and procedural flaws of the pardon by stressing that such a significant and unusual matter lacks even the president's handwritten signature.
Republican Senator Paul and the Republican leadership released 1,000 pages of Fauci's work journals from the COVID-19 period and claimed he concealed truths from the public. The newly released journals include an entry from January 2020 in which Fauci wrote, "The Huanan market in Wuhan, China, was not the source of the virus but an amplifier that fueled its spread." This suggests that even Fauci himself did not fully trust the Chinese government's statements from the early days of the outbreak. The journals also reveal that NIAID internally examined both the natural infection and lab leak hypotheses. The committee plans to vote on the 5th on whether to hold Fauci in contempt of Congress.
The scientific community pushed back against the hearing itself. In an open letter released ahead of the hearing, more than 150 scientists, including infectious disease experts, said, "No credible evidence has ever been presented to support the allegations," and urged, "Stop the witch hunt." A 2024 investigation by a congressional subcommittee led by Republicans also found no evidence linking Fauci to illegal conduct. However, with a key White House insider who had previously backed the natural-origin theory reversing course, and the top pandemic official of the time staying silent behind a blanket pardon, the controversy over the transparency of the Biden administration's pandemic response is expected to intensify.