Facebook founder Mark Zuckerberg and wife Priscilla Chan announced Tuesday they will donate $25 million to the U.S. Centers for Disease Control and Prevention to help contain and eliminate the Ebola virus that has killed nearly 4,500 people in western Africa. Zuckerberg’s announcement comes “at a critical turning point,” he wrote, adding the world has no choice but to act now.

The CDC says despite the threat of Ebola’s spread, it makes more sense to eliminate the disease where it’s most concentrated. Using this logic, the organization will use the donation to fund ongoing response efforts in Guinea, Liberia and Sierra Leone, as well as other places where Ebola is a major threat.

“The Ebola epidemic is at a critical turning point. It has infected 8,400 people so far, but it is spreading very quickly and projections suggest it could infect 1 million people or more over the next several months if not addressed,” Zuckerberg wrote on his own Facebook page.

“We need to get Ebola under control in the near term so that it doesn’t spread further and become a long-term global health crisis that we end up fighting for decades at a large scale, like HIV or polio.”

The Facebook founder and CEO’s check comes amid heightened measures to contain the epidemic. London’s Heathrow airport, following steps laid out by New York City’s JFK airport, has introduced a screening process that involves taking passengers' temperatures and requiring them to fill out questionnaires meant to determine whether they are at risk of contracting Ebola