Inequity in health is not new. Each year, more than 5 million children—almost entirely in low- and middle-income countries—die before their fifth birthday from mostly preventable diseases. Reducing this gap has been the Gates Foundation’s top priority for more than 20 years.

Still, the disparities in access to the COVID-19 vaccine are shocking and unjust. Only 2 percent of people in low-income countries have received any COVID-19 vaccines. And the gap may be getting even larger as rich-world governments buy up extra doses to serve as booster shots.

I wrote about two ways to achieve vaccine equity in the future. If the world makes the right investments and decisions now, we can make things better next time. And maybe even make sure there is no next time at all.