The fight against Ebola just got a big infusion of cash from Mark Zuckerberg and wife Priscilla Chan.

The Facebook CEO on Tuesday announced he and Chan have donated $25 million to the U.S. Centers for Disease Control and Prevention to fight against the deadly disease.

"The Ebola epidemic is at a critical turning point," Zucerberg wrote in a Facebook post. "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. 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 large scale, like HIV or polio."

Zuckerberg said he and Chan believe the grant is the quickest way to "empower the CDC and the experts in this field to prevent this outcome." The money will directly help frontline responders who are setting up care centers, training local staff, and identifying Ebola cases.

"We are hopeful this will help save lives and get this outbreak under control," he said.

Zuckerberg's grant comes after Bill Gates made a $50 million donation last month to fight Ebola via The Bill & Melinda Gates Foundation to support emergency efforts to contain the outbreak in West Africa and help stop its transmission.

In a statement, the foundation said the funds would immediately aid United Nations agencies and other international organizations involved in the response, enabling then to purchase supplies and scale-up emergency operations.

"We are working urgently with our partners to identify the most effective ways to help them save lives now and stop transmission of this deadly disease," Sue Desmond-Hellmann, CEO of the Gates Foundation, said in a statement. "We also want to accelerate the development of treatments, vaccines and diagnostics that can help end this epidemic and prevent future outbreaks."

In a report released Oct. 10, the World Health Organization said a total of 8,399 cases of Ebola have been reported in seven countries: Guinea, Liberia, Nigeria, Senegal, Sierra Leone, Spain, and the U.S. As of Oct. 8, there have been 4,033 deaths.