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.

Partisan divisions persist

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.

Drove 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 layered 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.”

Fauci and the Biden administration

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.

To be sure, there has been criticism from within the international scientific community that the lab leak theory was ed 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, but 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.”

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 used 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.