Ask anyone with a passing interest in global health what the Gates Foundation means to them and you'll likely get just one answer: money. In a field long fatigued by the perpetual struggle for cash, the foundation's eagerness to finance projects neglected by many other donors raised high hopes among campaigners that its impact on health would be swift and great. And with the commitment last June by America's second richest man, Warren Buffet, to effectively double the foundation's $30bn (£15bn; €22bn) endowment,1 hopes of substantial health achievements grew higher still.

But despite Bill Gates's prediction at a press conference to mark Buffet's pledge that there was now “No reason why we can't cure the top 20 diseases”2 observers are starting to question whether all this money is reaping sufficient rewards. For although the foundation has given a huge boost to research and development into technologies against some of the world's most devastating and neglected diseases, critics suggest that its reluctance to embrace research, demonstration, and capacity building in health delivery systems is worsening the gap between what technology can do and what is actually happening to health in poor communities. This situation, critics charge, is preventing the Gates's grants from achieving their full potential.

As one of the Gates Foundation's three main focuses, along with global development and its US programme, global health projects receive a substantial amount of the charity's annual spending. To date, almost half of all awards have been in this area, a total of $6bn. When the …