The future of four major research networks focused on HIV, tuberculosis, and emerging infectious diseases remains uncertain following weeks of delays by the Trump administration in launching the process to renew their funding. Researchers have expressed concern that these delays could threaten the continuation of the networks, which have been critical in testing vaccines and treatments worldwide.

On Friday, the National Institutes of Health (NIH) advised HIV researchers to pause initiating new studies that had not yet started enrolling participants and would not conclude before November 30, 2027, the expiration date of their current funding. This pause, stemming from delayed renewal processes, has raised alarms among scientists about potential disruptions to ongoing clinical trials and the safety of their participants.

Funding delays for medical research have become a persistent challenge during the second Trump administration. While there remains the possibility of renewal, researchers warn that interruptions could compromise timely progress, disrupt staffing and resources, and erode momentum crucial to long-term studies.

Dr. Emily Erbelding, a former leader of an infectious disease division at the NIH, emphasized the significant impact of losing funding momentum, noting uncertainty about whether current administration officials fully appreciate the consequences of such delays.

The Department of Health and Human Services (HHS), overseeing the NIH, has not provided a clear timeline for issuing the formal notices that would initiate the funding renewal process. A spokeswoman for HHS, Grace Davis Jamison, stated that the administration intends to continue investing in HIV research that produces “meaningful results,” but declined to address specific questions about the renewals.

The apprehension surrounding funding stems from several sharp cuts to HIV-related programs under the administration. These include reductions in foreign aid targeting HIV, significant staff layoffs at the Centers for Disease Control and Prevention’s HIV prevention division, and proposed budget cuts affecting HIV surveillance and prevention efforts nationwide. In 2023, the NIH terminated a $258 million multisite program instrumental in the search for an HIV vaccine.

Health Secretary Robert F. Kennedy Jr. has voiced his skepticism about HIV vaccine research, describing the federal investment as ineffective, a view that has influenced policy directions within the department.

The four networks affected include Advancing Clinical Therapeutics Globally, the HIV Prevention Trials Network, the HIV Vaccine Trials Network, and the International Maternal Pediatric Adolescent AIDS Clinical Trials Network. These networks have operated for decades across dozens of countries, conducting hundreds of clinical trials with annual budgets exceeding $300 million, primarily funded by the U.S. government. They have been central to developing tools to prevent and treat HIV, especially in hard-to-reach or vulnerable populations such as pregnant women, adolescents, and individuals resistant to multiple HIV drugs.

The networks' extensive infrastructure also facilitated rapid response during the COVID-19 pandemic, enabling the swift enrollment of tens of thousands of participants to test vaccines and treatments, including a monoclonal antibody therapy administered to then-President Trump.

Funding for these networks is renewed in seven-year cycles, requiring complex planning, including laboratory, organizational, and scientific agenda development. Many network leaders report that unlike previous cycles, there has been minimal communication or requests for input from NIH program officers this time. Notifications of funding opportunities, expected by late August, had not been released as of early August, further fueling uncertainty.

A federal official, speaking anonymously, confirmed that the notices were under review by HHS, led by Secretary Kennedy, who has overseen broad cuts across federal health programs. Additional political review layers under the administration have slowed the release of such funding opportunities.

NIH Director Dr. Jay Bhattacharya has also drawn criticism from some HIV researchers by advocating a shift from basic research on new vaccines and treatments toward studies optimizing the deployment of existing tools. While Dr. Bhattacharya supports long-acting treatments like lenacapavir, which involves twice-yearly injections, many experts argue that only a vaccine or cure will end the global epidemic, which still affects over 40 million people and causes more than 500,000 deaths annually.

Experts warn that interruptions in funding and clinical trials could stall progress and damage trust among communities historically wary of healthcare engagement. Dr. Wafaa El-Sadr, a leader of studies within the HIV Prevention Trials Network, highlighted the fragile and time-intensive nature of these efforts, cautioning that decades of work could be undone without sustained investment.

Concerns also include the possibility that NIH might dismantle the networks in favor of funding individual grants or restrict research to U.S.-based sites, potentially ending valuable international collaborations. HIV and many other infectious diseases are far more prevalent outside the United States, making global research sites essential.

Dr. Myron Cohen, a former network leader and professor at the University of North Carolina, Chapel Hill, underscored the importance of international research infrastructure by recalling how studies conducted in Africa rapidly advanced understanding of HIV transmission mechanisms—progress that would have been impossible to achieve in the United States within a comparable timeframe.

Researchers warn that the delayed funding decisions risk undermining critical infrastructure built over decades, which not only supports HIV/AIDS research but also bolsters responses to emerging infectious disease threats.