Sharp reductions in global development aid could undo decades of progress in fighting child mortality and infectious diseases across India, Asia and much of the developing world, according to a major new study published today in The Lancet Global Health.

The peer-reviewed analysis, led by the Barcelona Institute for Global Health (ISGlobal) with support from the Rockefeller Foundation, estimates that continued cuts to official development assistance (ODA) could result in 22.6 million additional deaths worldwide by 2030, including 5.4 million children under the age of five, across 93 low- and middle-income countries.

Researchers found that international aid between 2002 and 2021 played a decisive role in improving health outcomes, helping to reduce child mortality by 39%, deaths from HIV/AIDS by 70%, and fatalities from malaria and nutritional deficiencies by 56% each. The countries analysed account for roughly 75% of the global population, including India and 20 other nations across Asia.

The warning comes as international aid declined in 2024 for the first time in six years. Major donors such as the United States, the United Kingdom, France and Germany cut contributions simultaneously for the first time in nearly three decades, with further reductions projected through 2026.

“Development assistance is among the most effective global health interventions available,” said Davide Rasella, coordinator of the study and ICREA research professor at ISGlobal. “Withdrawing this support now would not only reverse hard-won progress, but would translate directly into millions of preventable adult and child deaths in the coming years.”

Asia and India at risk

While Sub-Saharan Africa faces the greatest proportional risk, the study highlights Asia’s vulnerability due to population scale. Twenty-one Asian countries — including India, Bangladesh, Pakistan, Indonesia, Nepal, Sri Lanka and Vietnam — are among those where decades of health gains could be reversed.

“Asia’s scale means that when health systems fail, the human cost is immense,” said Deepali Khanna, Senior Vice President and Head of Asia at the Rockefeller Foundation. “Without sustained and smarter development assistance, hard-won progress against disease can disappear.”

Two possible futures

The study models two scenarios for the period 2025–2030:

Under a mild defunding scenario, reflecting an average annual cut of 10.6%, an estimated 9.4 million preventable deaths could occur, including 2.5 million children under five.

Under a severe defunding scenario, based on current and worsening cuts totalling more than 15%, deaths could exceed 22.6 million, a figure the authors describe as equivalent to the combined populations of cities such as London, Paris and Barcelona.

Researchers used longitudinal data and country-level microsimulation models to assess the impact of funding reductions across all OECD donor countries. Beyond mortality, the study found that aid investments strengthened health systems, improved outbreak preparedness, and supported disease control and eradication efforts.

A global retreat

At least three out of every four people worldwide live in countries where development gains achieved over the past two decades could be undone, the authors warn. The analysis includes 38 countries in Sub-Saharan Africa, 12 in Latin America, 12 in the Middle East and North Africa, and 10 in Europe, including Ukraine.

“The question before humanity is whether we will accept a global retreat from commitments to feed the hungry and cure the sick,” said Dr. Rajiv J. Shah, President of the Rockefeller Foundation. “Budget decisions made today will have irreversible consequences for millions of people.”

The findings build on earlier ISGlobal research showing that dismantling the U.S. Agency for International Development (USAID) alone could lead to more than 14 million additional preventable deaths by 2030. Unlike that study, the new analysis evaluates the combined impact of cuts across all OECD donors.

The authors say the results underscore the need for renewed international cooperation and country-led financing strategies to protect vulnerable populations as global aid budgets shrink.