Washington, DC – A Senate committee hearing this week has once again shone a spotlight on the political divisions over the United States government’s response to the COVID-19 pandemic.

Wednesday’s hearing, held by the Senate Homeland Security and Governmental Affairs Committee, continued years of criticism, mainly from Republicans, against immunologist Anthony Fauci, who led the government’s response to the pandemic.

Spearheaded by committee chair Rand Paul, several Republicans rehashed claims that the virus that causes COVID-19, SARS-CoV-2, emerged from an infectious disease lab in Wuhan, China, and did not naturally transfer from animals to humans.

Stephen Morrison, the director of the Global Health Policy Center at the Center for Strategic and International Studies, said the hearing was a reflection of the deep, enduring partisan divides over the issue.

But he added that the meeting with Fauci did little to shed new light on the pandemic after years of investigation, hearings and political posturing.

“There’s no space for any civil discussion around any of these issues. There’s no desire really,” Morrison told Al Jazeera.

“So, what’s the lasting impact of this? I mean, it continues to impose unconscionable pain and suffering on [Fauci] and his family. It doesn’t advance the debate one inch on the whole question of COVID origins and what was past US policy and what should US policy be going forward.”

Wuhan lab leak theory

Wednesday’s hearing was based largely on a previous 520-page report from 2024, created by the Republican-led Select Subcommittee on the Coronavirus Pandemic.

That report claimed it was likely that SARS-CoV-2 emerged from the Wuhan Institute of Virology, a Chinese research facility. Senator Paul has embraced this viewpoint, as has President Donald Trump.

In April of last year, shortly after Trump took office for his second term, the White House launched a webpage purporting to reveal “the true origins of COVID-19”, largely based on the report.

The site highlighted several claims that experts say pave over the nuanced scientific debate about the origins of the virus.

Drawing on the 2024 report, the White House asserts that SARS-CoV-2 “possesses a biological characteristic that is not found in nature” and that “data shows that all COVID-19 cases stem from a single introduction into humans”, setting it apart from previous natural pandemics.

Joel Wertheim, a professor of medicine at the University of California San Diego, told Factcheck.org that both claims were false.

While COVID does contain a characteristic to enter cells that is not found in its closest coronavirus relatives, that quality does exist in other coronaviruses more broadly. As Wertheim put it, “It is most certainly found in nature.”

Meanwhile, a pair of studies released in 2022 found at least two unique paths through which initial human infection occurred, contradicting the White House’s claim that the pandemic arose from a “single introduction into humans”.

The White House webpage also focuses on Fauci, who led the National Institute of Allergy and Infectious Diseases (NIAID) until 2022 and served as the chief medical adviser to former US President Joe Biden, Trump’s election rival.

Biden pre-emptively pardoned him in January 2025, fearing the physician might be arrested under the second Trump administration.

Ahead of Wednesday’s hearing, Trump took the opportunity to renew his derision of Fauci, writing on Truth Social that the medical expert’s “ideas were CRAZY”.

Trump also accused Fauci, without evidence, of orchestrating a cover-up for China, where COVID was first documented. The Republican leader was serving his first term as president when the pandemic began.

Ongoing debate

To be sure, there has been criticism from within the international scientific community that the lab leak theory was discounted too swiftly in the early days of the pandemic, as it became seen as political.

Trump and other world leaders had been quick to use anti-China rhetoric when discussing the virus.

There currently remains no conclusive evidence proving either the lab leak theory or that the virus had a natural origin. The vast majority of infectious disease scientists, including Fauci, have said neither possibility can be ruled out.

Still, a preponderance of experts say evidence indicates that the virus was most likely transferred from an animal, likely a bat, to humans, in a process called zoonotic spillover.

A 2024 survey of virologists and other scientists, conducted by the Global Catastrophic Risk Institute (GCRI), found most respondents believed natural transmission was considerably more likely than a lab leak, although most acknowledged it was impossible to definitively dismiss the theory.

Following three years of research, a World Health Organization (WHO) advisory board released a report in 2025 that also concluded “the weight of available evidence … suggests zoonotic spillover”.

Still, WHO director Tedros Adhanom Ghebreyesus cautioned, “As things stand, all hypotheses must remain on the table, including zoonotic spillover and lab leak.”

Inside Fauci’s diary

Fauci has long argued the scientific evidence indicates that the virus emerged from natural animal transmission, but he has repeatedly rejected the notion that he has outright dismissed the lab leak theory.

In a 2024 letter to the House Subcommittee on the Coronavirus Pandemic, his lawyers maintained (PDF) it was “completely wrong” to say that Fauci had ever called the possibility a “conspiracy theory”.

Instead, they said Fauci and his allies rejected an array of conspiracy theories that have been tied to the lab leak theory, including the idea that he had “sneaked unnoticed into the CIA headquarters to try to convince CIA officials to debunk the lab leak theory”.

Wednesday’s hearing was preceded by the release of entries from Fauci’s private diary, stored on a government computer drive.

They were obtained through Health and Human Services Secretary Robert F Kennedy Jr, a vaccine sceptic and Fauci critic, who passed them along to Senator Paul.

In one entry, Fauci described a claim that he “deliberately” worked with the Chinese to create the virus as a “way-out conspiracy theory”.

He and his legal team have also repeatedly rejected Republican claims that he leveraged millions in grant money to compel scientists to change their views about COVID’s origins.

The White House website, for instance, asserts that Fauci “prompted” an early study on COVID origins to downplay the lab leak theory. No evidence has been presented to support those claims, which have also been rejected by the scientists involved.

Did Fauci mislead?

On Wednesday, several Senate Republicans charged that Fauci’s diary entries showed he had intentionally misled the public by downplaying the possibility the virus had emerged from the Wuhan lab.

Fauci’s supporters, however, have said the diary fails to prove any deliberate attempt to mislead. They argue his public and private statements were consistent in the early days of the pandemic, when scientists’ understanding of the virus was shifting daily.

Fauci’s diary entries indicated he met with a group of experts in February 2020, noting “there was not total agreement” on the likelihood the virus had been created via human manipulation. Senator Paul and others said Fauci did not adequately reflect that view in his public statements.

Republicans also seized on a January 26, 2020, entry in which Fauci wrote that initial data suggests “the first infection was in early December and was not connected” to the wet market in Wuhan.

“Now we know the market was not the source but the amplifier,” he wrote.

During the hearing, Senator Paul said the diary revealed that Fauci was “repeatedly saying in public something different than what he believes in private”.

Fauci’s defenders have pointed to a USA Today interview he gave shortly after the diary entry, floating the idea that the market could have been an “amplifier”. Others have argued the diary entries do not contradict the view that the virus was of natural origins.

Public restrictions

Republicans on Wednesday also focused heavily on Fauci’s role in issuing public guidance about how to slow the spread of the COVID virus.

Several states saw schools close and businesses shutter amid social-distancing recommendations.

But those closures became a political lightning rod and featured prominently in the 2020 presidential elections and 2022 midterm races.

Indeed, new studies have cast doubt on the effectiveness of social distancing rules. Others indicate mask mandates may have been less effective than previously presented, although research still generally supports that masks may slow the spread of the disease.

As NIAID director, Fauci had no direct authority to impose public health mandates, which were typically introduced by state and local officials. While he had a role in issuing federal guidance, his work was part of a wider government effort involving other agencies and officials.

Speaking on Wednesday, Gary Peters, the top Democrat on the Senate panel, accused Republicans of “relitigating history” and seeking to “turn one person into a scapegoat for a crisis that hundreds of officials across the Biden and Trump administrations were responsible for handling”.

Still, Fauci’s diary does contain uncomfortable revelations about how he wielded his high-profile position. In one instance, he recounted how he offered then-New York City Mayor Bill de Blasio encouragement to close city schools. He did the same with an aide to California Governor Gavin Newsom.

“I advised De Blasio to go ahead and do it,” he recounted. “I went on to tell him he should close the bars and restaurants in NYC… He said that he would base this on my recommendation.”

Why now?

During the Wednesday hearing, Fauci invoked his constitutional right to remain silent roughly 100 times, drawing significant public scrutiny.

The 85-year-old Fauci, who enjoyed bipartisan support as NIAID director throughout much of his 38 years in the role, decried the hearing as an attempt to entrap him with perjury.

Critics, including several Democrats on the committee, have also questioned the timing of Wednesday’s hearing, which comes just three months before November’s midterm elections.

Republicans are expected to face an uphill battle in maintaining control of the House of Representatives, and they also risk losing their slim control of the Senate in the vote. A defeat in either chamber would serve as a major setback to Trump in his final two years in office.

The party has struggled to find a defining issue to campaign on, amid affordability woes fuelled by the ongoing US-Israeli war with Iran.

The hearing also comes at a time when polls have shown public trust in federal health agencies has plummeted since Trump took office.

For instance, a June poll conducted by the Harvard TH Chan School of Public Health and the de Beaumont Foundation’s Public Health Listening Lab suggests that just 50 percent of respondents said they trusted recommendations from the Centers for Disease Control and Prevention (CDC).

That marks a decline from 77 percent in the spring of 2025.

About 69 percent also felt that federal health agencies’ recommendations were too influenced by their leaders’ public opinions.

But Morrison, the health policy expert, saw the hearing as a personal attack on Fauci, with Senator Paul and Secretary Kennedy pursuing an ideological “vendetta”.

Fauci, he said, has come to represent for some Republicans the “iconic embodiment of everything that they have come to believe is craven and corrupt in the US government response” to COVID.

He warned that their approach, though, could chill any desire for top scientists to wade into government.

“People will say Tony Fauci could have done things a little differently, he made a few mistakes, and he could have admitted those,” Morrison said.

“But the ‘big but’ is certainly none of that warrants what’s happening here.”