President 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…