There’s good news and bad news in the world of global health research.
The good news is that the gap between what health scientists are studying and the actual worldwide disease burden has narrowed since 1999. That’s according to a new study from a global team of health policy researchers, including Georgia Tech’s Cassidy R. Sugimoto.
The bad news? The study shows the improvement was mostly accidental, and things are likely to start getting worse again — especially if the U.S. follows through on plans to cut global health research funding.
“Our current situation is going to lead to an increasing imbalance between the diseases burdening the world and the research that is produced,” said Sugimoto, the Tom and Marie Patton Chair in the Jimmy and Rosalynn Carter School of Public Policy.
The findings are detailed in a paper published Aug. 27, 2025, in Nature Medicine.
An Accidental Alignment
The idea that research and disease burden are mismatched isn’t new. In fact, the paper cites a longstanding rule of thumb stating that only 10% of health research funding goes to diseases that make up 90% of the global disease burden.
However, this paper's approach is new in key ways that go beyond this "10/90 gap" concept. While that concept provided a static snapshot of the problem, this study created a two-decade-long analysis of how the gap evolved and where it's heading next.
The authors used a "triangulated large language model approach" that they validated as being significantly more precise than older coding methodologies, with the AI tools achieving 94.9% accuracy in correlating articles with diseases, compared to 67.0% for traditional methods.
In the study, Sugimoto and her co-authors from the University of Mannheim, the University of Zurich, and Heidelberg University Hospital used those AI tools to examine 8.6 million research papers published over two decades, comparing them to the Global Burden of Disease database maintained by the Institute for Health Metrics and Evaluation at the University of Washington.
They found the gap between research and real-world health problems had narrowed significantly over the study period, 1999 to 2021. However, this progress was not because scientists changed their focus. Rather, the global disease landscape had shifted to better match the static priorities of the research community.
"The data show a seemingly increased alignment of research and burden of disease over the past two decades, driven almost entirely by changes in the burden of communicable diseases, while research has remained largely unchanged,” the authors wrote.
A Widening Gap Ahead
For decades, widespread public health interventions have reduced the impact of communicable diseases. As that burden shrank, the world’s health problems began to look more like what scientists were already studying. Now, with fewer gains to be had fighting communicable diseases, and with chronic, "Western-style" diseases on the rise globally, the researchers project the gap will widen again.
“We find a dichotomy of more local communicable diseases, which have seen a decline in divergence of about 75%, and more global noncommunicable diseases, which have seen a 25% increase in divergence,” according to the paper.
The reason for the widening gap is that most research into chronic diseases isn’t truly global, the researchers argue. Scientists, heavily concentrated in Western countries, tend to focus on problems and solutions applicable to their own populations, which often have access to advanced healthcare systems and technologies unavailable in many parts of the world. And that doesn’t seem to be getting better, the researchers say.
“Paradoxically, as disease patterns become more globally integrated, recent evidence suggests that scientific research is becoming more fragmented, with declining international collaboration overall,” the researchers said.
Covid-19: An Exception That Proves the Rule
The Covid-19 pandemic serves as a powerful exception to the study's main findings. The authors found that as the pandemic surged, the scientific community demonstrated a remarkable ability to pivot and rapidly align its focus with the emerging crisis. This was a stark contrast to the static, two-decade-long trend observed for most other diseases.
The data show that the share of the global disease burden from respiratory infections such as Covid-19 doubled between 2019 and 2021. In response, the proportion of global research dedicated to this category quadrupled, rising from 3% in 2019 to between 12% and 14% in 2020 and 2021.
According to the paper, this proves "the capacity of the global research system to align rapidly with emerging health challenges," suggesting that the usual lack of alignment is a problem of priorities and incentives, not capability.
Funding Cuts Could Further Widen the Gap
However, such pivots are highly dependent on funding, and one particular risk, the researchers say, is the decision by U.S. officials to reduce funding for international health science research, including initiatives such as U.S. Agency for International Development (USAID), the President's Emergency Plan for AIDS Relief (PEPFAR), and the vaccine alliance Gavi.
According to the paper, a sustained withdrawal of U.S. funding could reverse nearly half of the progress made in aligning research with disease burden over the last 20 years.
Such cuts would harm research on both communicable and non-communicable diseases, including HIV/AIDS, respiratory diseases, tuberculosis, neurological disorders, and substance use disorders, the researchers say.
Sub-Saharan Africa is at particular risk, the researchers say, given that 84% of U.S. global health funding went to that part of the world as recently as 2023. That money supported 41% of research into sexually transmitted diseases in the region and 25% of the region's research on respiratory infections and tuberculosis.
More broadly, the researchers warn that uncertainty from funding terminations affects the entire global research enterprise, including "international science research networks, capacity-building global health partnerships and multi-country clinical trials."
Forging a More Aligned Future
To counteract these trends, the authors argue for a deliberate and coordinated global effort to realign research with health needs across three fronts:
- Finding ways to support governance structures that can withstand national or regional political shifts to ensure funding and incentives are directed toward the most pressing global health priorities.
- Investing in "locally led research capacity," especially in the regions where the disease burden is growing fastest. This approach, the researchers say, avoids "helicopter science" — where Western researchers collect data and leave. Instead, this approach builds sustainable, local expertise to develop solutions that are practical and effective in their own communities.
- A greater commitment to open science and shared data infrastructure. More openness would allow for transparent, real-time tracking of how well research is aligning with disease patterns, enabling funders and policymakers to make more evidence-based decisions.
“Policy action, like open science and data sharing mandates, is needed to make progress in aligning global research efforts with evolving disease burdens. This will facilitate the acceleration of research in traditionally less research-intensive countries, which become increasingly affected by the burden of non-communicable diseases,” according to the researchers.
The paper, “Global Distribution of Research Efforts, Disease Burden, and Impact of US Public Funding Withdrawal,” appeared Aug. 27, 2025, in Nature Medicine. It is available at https://doi.org/10.1038/s41591-025-03923-0.