San Francisco-based drone startup Zipline Inc. announced it closed a $25 million Series B funding round led by Visionnaire Ventures, along with investments from Andreessen Horowitz, Yahoo Inc. cofounder Jerry Yang, Sequoia Capital and Subtraction Capital.

The latest round brings Zipline’s total funding up to $43 million, which the company says will allow it to expand its operations to new countries.

While some companies like Google and Amazon have been testing out drone deliveries with Chipotle burritos and shoes, San Francisco-based startup Zipline Inc. have put drones to work in a slightly more humanitarian role: delivering blood and medicine to difficult to reach locations in Africa and elsewhere. In fact, Zipline launched the world’s first commercial drone service through a partnership with the government of Rwanda.

Building roads to remote locations requires a significant amount of time and resources, and even though Rwanda does have roads in many areas, those roads often become impassable due to seasonal flooding. As a result, many of Rwanda’s hospitals find it difficult to restock their supplies of blood and medicine, and Zipline set out to solve this problem by using drones to bypass the roads entirely.

According to Zipline, its drones are capable of delivering packages weighing up to about 3.3 pounds across distances of nearly 100 miles, all while travelling at a breakneck speed of roughly 62 miles per hour. This allows Zipline to deliver medical packages across nearly the entire country of Rwanda while launching from a single centralized location.

For its project in Rwanda, Zipline also formed a partnership with United Parcel Service of America Inc. and Gavi, the Vaccine Alliance, which included an $800,000 grant to help Zipline further develop its technology and infrastructure in the country.

“The inability to deliver life-saving medicines to the people who need them the most causes millions of preventable deaths each year. The work of this partnership will help solve that problem once and for all,” Zipline cofounder and Chief Executive Keller Rinaudo said at the time. “With the expertise and vision of UPS, Gavi and Zipline, instant drone delivery will allow us to save thousands of lives in a way that was never before possible.”

According to Zipline’s website, there are roughly 150,000 pregnancy-related deaths each year that could be prevented with reliable access to safe blood supplies.

Images courtesy of Zipline