 In a previous study, the most common pneumococcal serotypes or groups from developed countries were found to be, in descending order, 14, 6, 19, 18, 9, 23, 7, 4, 1 and 15.In developing countries, the order was 6, 14, 8, 5, 1, 19, 9, 23, 18, 15 and 7.In order to further pneumococcal vaccine research and reduce childhood mortality, five countries and the Bill & Melinda Gates Foundation established a pilot Advance Market Commitment for pneumococcal vaccines worth US$1.5 billion.