A Boston-based biotech company will partner with the Bill and Melinda Gates Foundation in a $140 million effort to prevent HIV in sub-Saharan Africa.There's a vital need for an HIV/AIDS intervention that allows those at risk to incorporate prevention more easily into their daily lives, said Sue Desmond-Hellmann, chief executive of the Gates Foundation, in a statement. We feel optimistic about our partnership with Intarcia and the prospect of an implantable prophylactic device that could make a world of difference for people more in need.