New medicines are usually financed by a mixture of public funding by governments, philanthropic giving, and investment by private firms. Private investment is especially important in paying for and managing the later stages of clinical trials, regulatory approval, and investment in manufacturing capacity. But for diseases that mainly affect people in developing countries, the prospective sales market is tiny—and not sufficient to justify commercially the large scale investment that is needed to develop new products.
An advance market commitment to accelerate the development of vaccines for diseases concentrated in developing countries, donors could make a binding commitment to pay for a desired vaccine if and when it is developed. This advance market commitment would mean firms could invest in finding a vaccine with the confidence that if they succeed there would be a market for the product.