The Advance Market Commitment scheme, formulated by the GAVI Alliance, aims to provide more vaccines to the developing world by fixing their price over a 10-year period. Is it going to deliver, what will be the result, and how did global health institutions and the big pharmaceutical companies manage to agree on such a deal? 

Kids in developing countries need vaccines, but will the world's wealthy financial markets really help to deliver them? A deal brokered by former British Prime Minister Gordon Brown has so far raised nearly $2 billion for just that purpose. It's called the International Finance Facility for Immunisation (IFFIm), and author Aminatta Forna wants to know how it works.