Years of Work Toward a Vaccine Abruptly Cut Off
After nearly 15 years of focused research, immunologist Dennis Burton was preparing to begin trials on a promising HIV vaccine candidate. His team’s efforts, backed by a $258 million government grant, were part of one of the most advanced programs in the field. But on May 30, he received notice that the project would not continue. Federal officials announced the program would be terminated next year, forcing a halt to preparations.
“This is devastating,” Burton said. “We were finally seeing a real possibility of success, and now it’s being dismantled.”
A Complex Virus Meets a Complicated Bureaucracy
HIV’s rapid mutation rate makes vaccine development uniquely difficult. The virus can produce numerous variants even within a single individual, allowing it to evade immune responses. Burton’s group, a collaboration between researchers at Scripps and Duke University, focused on teaching the immune system to generate broadly neutralizing antibodies — a type of immune response capable of targeting many HIV variants.
The strategy had gained momentum globally and was scheduled to enter clinical testing in 2025. But with the program’s cancellation, trials will not proceed. A spokesperson for the U.S. Department of Health and Human Services said the decision was based on concerns about overlapping initiatives and the need to better allocate taxpayer funds.
Yet many scientists argue that multiple approaches are necessary. Mark Feinberg, a leading expert in vaccine development, explained that diverse strategies can offer valuable synergies and increase the chances of success. “You don’t know in advance which model will work best,” he noted.
The setback is part of a broader reduction in support for HIV vaccine development. In 2022, the U.S. contributed nearly 90% of the world’s HIV vaccine research funding — a figure now expected to drop significantly. The loss of financial backing could force promising vaccine candidates into indefinite suspension.
African-Led Initiative Frozen Days Before Trial Launch
Another example of this shift is the sudden halt of a multinational vaccine trial that was set to begin in Africa earlier this year. Led by biomedical scientist Linda-Gail Bekker, the BRILLIANT HIV vaccine consortium had secured a $45 million grant in 2023 to run clinical trials across eight countries. Just days before launching the first human trial, the group received a stop-work order.
“We were heartbroken,” Bekker said. “Years of building this effort — bringing together global scientists, local communities, and regulatory bodies — just stopped without warning.”
The consortium had developed immunogens derived from HIV variants identified in South Africa, aiming to trigger production of the same powerful antibodies observed in certain patients who naturally control the virus. These trials were designed to test vaccines in populations most affected by the epidemic — an essential step in understanding real-world efficacy.
Now, Bekker’s team is seeking emergency funding to salvage what they can. She emphasized that the original grant’s scope and reach cannot easily be replaced. “Running smaller trials means lower-quality data and slower progress,” she warned.
Restrictions on Foreign Partnerships Threaten Global Progress
The funding challenges extend beyond trial delays. In May, U.S. authorities announced that they will no longer support foreign subawards, which are a common mechanism allowing U.S.-based researchers to collaborate with international partners. In 2024 alone, more than 3,600 of these awards were granted. Moving forward, foreign researchers must apply directly for funds — a shift that many believe will severely limit participation.
“This affects more than just research logistics,” said Susan Zolla-Pazner, an HIV scientist. “Diseases like HIV are global. You can’t study maternal transmission or vaccine efficacy without reaching the right populations, which often aren’t in the U.S.”
She warned that these new restrictions act as more than an obstacle — they are a structural barrier. Important trials, such as those focused on preventing mother-to-child transmission in high-prevalence regions, may no longer be feasible.
Experts Warn of Long-Term Consequences for Public Health
Meanwhile, over 2,500 government-funded research grants — including several linked to HIV vaccine efforts — have been delayed or canceled. Many scientists also note that interest in mRNA vaccine technology, which accelerated COVID-19 vaccine development, appears to be waning within federal agencies.
Together, these changes are fueling concern that the momentum gained after decades of HIV research may be lost. With proposed budget cuts of over 40% for NIH grants next year, some researchers worry that recovery may be impossible.
Burton fears that without sustained support, scientific leadership in this field will shift away from the U.S. “Other countries won’t easily step in to fill the gap. And private philanthropy can’t replace this scale of investment.”
Even if funding resumes in the future, many research teams may not recover. Once key personnel leave and collaborations dissolve, restarting projects becomes extremely difficult.
“You can’t just hit pause and pick up where you left off,” Zolla-Pazner noted. “Once people move on, the continuity is lost.”
Still, some researchers believe that recent discoveries offer a foundation worth preserving. “We’ve made real progress — that’s undeniable,” said Bekker. “But now we’ve lost time, and in public health, time translates directly into lives.”
