President Joe Biden’s decision to donate 500 million COVID-19 vaccines to other countries by June 2022 is an important step toward restoring the United States’ global standing.

Another parallel foreign policy solution could perhaps do even more. It is simple, cost-effective and could improve the health and well-being of billions of people, especially children.

Inexpensive treatments — as little as 50 cents per child — can prevent neglected tropical diseases (NTDs), such as intestinal worms, that are among the most common illnesses affecting the world’s poorest and most marginalized people.

New evidence confirms that ensuring widespread access to NTD treatments generates clear health and humanitarian gains, while yielding remarkably high, and sustained, economic returns to society. As many nations turn inward, the U.S. should seize the opportunity to expand its support for proven, cost-effective solutions to global health challenges.

While the COVID-19 pandemic is ravaging the developing world, infecting hundreds of thousands of people daily and pushing many into poverty, more than 1 billion people, nearly one-seventh of the world’s population, continue to suffer from tropical diseases such as elephantiasis, trachoma, river blindness and intestinal worm infections, which cause severe pain, illness and long-term disabilities.

In fact, the pandemic has exacerbated the harm caused by these diseases by complicating mass-treatment efforts, including those based at schools, which have been shuttered in many countries for long stretches.

Among children, the impacts of NTDs are particularly acute. Infections cause malnutrition, impair intellectual and cognitive development and stunt growth. These illnesses undermine productivity and growth, and stymie progress toward global health and development goals.

Yet these diseases are largely preventable, and most can be treated with a few simple and inexpensive pills.

Compared to the enormous feat required to develop and deliver the COVID-19 vaccine, you would think governments would see NTD treatment as a quick, obvious win. Yet, the opposite is true.

Increasing demands on government budgets because of the pandemic are forcing many to cut support for NTDs, halting — and potentially even reversing — hard-won progress. The British government, a longtime global leader in foreign assistance, recently announced that it would cut 90% of its funding for these diseases as part of budget reductions caused by the financial double-whammy of the pandemic plus Brexit.

As a result, millions of people will go untreated and, tragically, many medicines that are already in-country will expire on the shelf because of a lack of funds to distribute them. For the world’s most vulnerable populations, the consequences will be catastrophic.

The United States is already a treatment leader on NTDs. It has allocated $988 million to this program since 2006, helping provide 2.8 billion treatments worldwide. Now, the Biden administration should encourage other wealthy countries to deepen their investment. Doing so will have significant impacts on long-term social and economic outcomes, enabling a more rapid and equitable recovery from the current global pandemic.

Edward Miguel is the Oxfam Professor of Environmental and Resource Economics and faculty director of the Center for Effective Global Action at UC Berkeley.