When Donald Trump nominated Jay Bhattacharya to be the director of the National Institutes of Health, a shake-up seemed inevitable. Typically, the agency—a $48 billion grant-making institution and the world’s largest public funder of biomedical research—has been led by a medical researcher with extensive administrative experience. Bhattacharya was a health economist without specialized training in infectious disease, who’d come to prominence for his heterodox views on COVID policies and who has criticized the NIH for stifling dissent.
The NIH has been transformed this year. And most of the layoffs, policy changes, and politically motivated funding cuts—notably, to infectious-disease research—have happened under Bhattacharya’s watch. But inside the agency, officials describe Bhattacharya as a largely ineffectual figurehead, often absent from leadership meetings, unresponsive to colleagues, and fixated more on cultivating his media image than on engaging with the turmoil at his own agency. “We don’t really hear from or about Jay very much,” one official told me. (Most of the current and former NIH officials who spoke with me for this article requested anonymity out of fear of retaliation.) Many officials call Bhattacharya “Podcast Jay” because of the amount of time that he has spent in his office recording himself talking. “Bhattacharya is too busy podcasting to do anything,” one official told me.
Instead, Matthew Memoli, the agency’s principal deputy director, “is the one wielding the axe,”the official said. This time last year, Memoli was a relatively low-ranking flu researcher at the NIH's National Institute of Allergy and Infectious Diseases (NIAID). Then, in January, the Trump administration appointed him to be the agency's acting director. At the time, other NIH officials considered Memoli to be a placeholder, temporarily empowered to carry out the administration’s orders. But “there’s been no change since Jay got put in,” one NIH official told me. To the agency officials I spoke with, Memoli, now second in command, still looks to be very much in charge.
Neither Bhattacharya nor Memoli agreed to an interview, and the NIH did not respond to a request for comment. So to better understand their leadership, I spoke with 18 current and former NIH officials, whose positions at the agency have spanned a breadth of specialties and administrative roles, and reached out to several of Bhattacharya’s former colleagues. The officials’ first impressions of Bhattacharya—who has argued that the NIH could do more “to promote innovative science”—were of an outsider and a radical, whose ideas could have changed the agency for better or worse. In recent months, NIH officials have come to see him as so disengaged that they hardly worry about his impact. Memoli, by contrast, knows just enough about the agency—and, in particular, its approach to infectious disease—to help destroy it.
Memoli’s appointment to acting director in January floored his colleagues—many of whom had never heard his name before. Like Bhattacharya, Memoli had no previous track record of executive leadership or in overseeing the awarding of federal grants. But officials quickly deduced what about Memoli might have appealed to the administration: In 2021, he described COVID-vaccine mandates as “extraordinarily problematic” in an email to Anthony Fauci, then the director of NIAID, whom the Trump administration has repeatedly tried to discredit. Then, last year, when asked to submit a routine statement about diversity, equity, and inclusion, Memoli sent in one that called the term DEI “offensive and demeaning.” By September, the NIH, under Bhattacharya’s leadership, had done away with DEI statements for its scientists, describing them as “loyalty oaths” that Memoli had “courageously stood against.”
In his two months as acting director, Memoli enacted the Trump administration’s agenda with aplomb, pushing through the mass cancellation of grants focused on topics such as DEI, transgender health, and COVID-19; multiple NIH leaders were ousted while he was acting director, including Jeanne Marrazzo, who served as the director of NIAID until early April. “His major function was to do the administration’s bidding,” Michael Lauer, who led the NIH’s grant-making division before he departed the agency in February, told me.
That same month, while Memoli was still acting director, he began to call Health Secretary Robert F. Kennedy Jr.’s attention to the flu-vaccine research he’d done with his mentor, Jeffery Taubenberger, another NIAID scientist. By early May—after Memoli had been installed as Bhattacharya’s deputy, and Taubenberger as the acting director of NIAID—HHS had redirected about half a billion dollars, once set aside to develop new COVID-19 vaccines and drugs, to their vaccine work. (Outside researchers criticized the grant as an unjustifiably enormous sum; in an email to me in May, Memoli insisted that the grant would support “more than one project,” but did not answer follow-up questions about how much of that sum would furnish his research specifically.)
Part of a deputy’s job is to take some load off the director. But under normal circumstances, people “wouldn’t really notice who the deputy director is,” one official told me; the director is expected to set policy and lead. Although Bhattacharya has continued to reiterate his own goals for the NIH—including advancing more innovative research—his recent visions for the agency have largely followed administration talking points such as diverting resources toward chronic disease and clamping down on “dangerous” virological research. Yet the director seems out of touch with the reality of that agenda: In his public appearances, internal meetings, and on social media, Bhattacharya has delivered conflicting and sometimes erroneous accounts of the NIH’s grant-making policies. Both publicly and internally, he has fixated more on defending himself against criticism he received for his COVID-policy views from 2020 than on the NIH’s current state of affairs, several officials said.
Bhattacharya, in his own way, still seems to be serving the administration by championing its talking points. But Memoli is the one most visibly throttling the NIH’s capacity to fund research and pushing out some of the agency’s most experienced and internally respected leaders. To officials at the agency, his actions look like those of a leader who has been given broad discretion to shrink down the agency’s infectious-disease work—an area where he may have a few personal grievances. “People are afraid of him,” one official said, pausing. “I’m afraid of him.”
Memoli’s history at the NIH appears to have given him a particular zeal for dismantling it. In his two decades at the agency, Memoli has developed a reputation as a self-aggrandizing co-worker, eager to champion himself and dismissive of people he hasn’t felt he could benefit professionally from, three officials who worked with him prior to 2025 told me. At various points, scientists at the agency lodged complaints about his unprofessional behavior toward colleagues, two NIH officials told me. Memoli, meanwhile, complained that “he wasn’t being given enough,” one of them said. Some of his scientific work was solid, but peers inside and outside the agency criticized some as unremarkable, leaving Memoli with a chip on his shoulder, the two officials said.
Of the NIH’s 27 institutes and centers, NIAID, where Memoli once worked, has been among the hardest hit this year, losing most of its senior leadership and a large number of its infectious-disease-focused grants. Since January, multiple officials who denounced the administration’s stance on infectious diseases and vaccines have had Memoli brush aside their concerns in meetings, then been ousted from their roles, three officials told me.
Given the Trump administration’s desire to pare down infectious-disease research, NIAID and prominent officials such as Marrazzo, who succeeded Fauci as director, were always clear targets for cuts. (Yesterday, Marrazzo filed a lawsuit that named Memoli and Bhattacharya and that alleged that she was illegally fired after she had filed a whistleblower complaint about actions of NIH leadership that endangered public health; the Department of Health and Human Services declined to comment on the lawsuit.) But in some cases, three officials told me, Memoli appears to have pushed lesser-known officials out of their roles after more personal clashes, including Sarah Read, who was NIAID’s principal deputy director and who repeatedly questioned the circumstances of Memoli and Taubenberger’s sizable vaccine grant. (Read has since left the agency.) Memoli also recently detailed Carl Dieffenbach, the director of NIAID’s Division of AIDS, to another branch of NIH after the two clashed over the administration’s approach to HIV research. Days later, he gave Dieffenbach a scoring of one out of five on a performance review—potential grounds for termination—before human-resources personnel forced him to revise that rating, because he lacked evidence for them, two officials told me. (Read and Dieffenbach declined to comment.)
Memoli has also argued that funding for HIV-vaccine research—which Dieffenbach oversaw—is wasteful and should be cut. The NIH is expected to soon divert up to a third of its AIDS budget toward improving the delivery of existing HIV tools, such as the new drug lenacapavir. At least some of that push has come from Bhattacharya, who has publicly advocated (including on his own The Director’s Desk podcast) for reallocating HIV funds on the grounds that established interventions could resolve the AIDS crisis on their own. But whereas Bhattacharya has waffled when asked how such an investment would affect other research, two officials told me, Memoli has insisted in internal meetings that it should come at the expense of research into HIV vaccines, which is widely considered to be essential to ending the HIV pandemic. Despite being a vaccine researcher himself, he’s “gleefully making these cuts,” one official told me. “Because it means he did something.”
Allowing Memoli to be the executor of the Trump administration’s cuts could serve the independent-thinker persona that Bhattacharya has tried to cultivate. But the NIH officials I spoke with, and one scientist who knew Bhattacharya prior to his appointment at the agency, doubted that his distance was so calculated. Trying to discredit the scientific establishment from the sidelines is far easier than trying to enact reform from its center. At the NIH, the embittered insider may leave the more memorable legacy.
