Gates Foundation donates $250-mln to fight Covid-19 pandemic
"But these innovations will only save lives if they get out into the world," he said.
Funding is one of the biggest hurdles for Africa, home to some of the world's poorest countries.
The World Health Organization has identified the goal of vaccinating three percent of Africans by March 2021 and 20 percent by the end of next year.
But it said only around a quarter of 47 countries on the continent have enough plans for resources and financing.
Coordinator for the Gates Foundation's Covid-19 response in Africa, Solomon Zewdu said part of the funding announced Thursday would help ensure that vaccines reach some 780 million people on the continent.
"The focus right now is to say ...how do we get those vaccines beyond the tarmacs of particular airports like, you know Addis Ababa airport, Kinshasa, Lagos into communities and immunise people. Unless that's done then we haven't done the work."
WHO estimates that getting the vaccine to "priority" population sectors in Africa will require $5.7 billion, plus 15-20 percent for delivery, syringes and other injection material.
Africa has recorded more than 2.3 million cases, of which 54,800 have been fatal.
South Africa, which with more than 828,000 cases is the continent's worst-hit country, on Wednesday said it had now entered a second wave of the pandemic.