The Bill & Melinda Gates Foundation is investing up to $140 million in Intarcia Therapeutics Inc. as part of an effort to combat HIV.

Intarcia Therapeutics is developing an anti-HIV vaccine that would be administered annually or semi-annually in sub-Saharan Africa and other countries where the epidemic is most severe.

The company attracted funding from the Gates Foundation during its second series EE equity financing which yielded $206 million in proceeds.

The Gates Foundation committed $50 million during the financing and has agreed to pay up to a further $90 million in milestone-related payments to the HIV vaccination.