Mark Zuckerberg and his wife Priscilla Chan have donated $25 million through their foundation to a philanthropic effort organized by Bill Gates to explore new coronavirus treatments. 

The Gates Foundation donated $50 million last week to what it’s calling the “COVID-19 Therapeutics Accelerator.” The initiative brings together life sciences companies to collaborate on the development of new vaccines, diagnostics, and treatments for COVID-19.

“The Therapeutics Accelerator will enable researchers to quickly determine whether or not existing drugs have a potential benefit against COVID-19,” Chan and Zuckerberg said in a press release. “We hope these coordinated efforts will help stop the spread of COVID-19 as well as provide shared, reusable strategies to respond to future pandemics.”

The two donations are the largest from tech billionaires since the coronavirus outbreak. Wellcome and Mastercard are supporting the effort as well. 

The goal of the initiative is to either develop a new drug or adapt an existing treatment that it could help distribute alongside partnering pharmaceutical companies. 

The 15 companies participating in the project kicked off the effort by sharing their proprietary libraries of molecular compounds that have some history of being tested with COVID-19. 

The lineup includes big names in biotech such as Johnson & Johnson, Merck, Pfizer, Sanofi, and Bristol-Myers Squibb.