Global Leaders At The Gavi Alliance Conference In London [Getty Images]

Bill Gates meeting delegates as Global leaders gather for the Gavi Alliance conference to drive a new, forceful impetus to immunisation efforts in the worlds poorest countries on 13th June 2016 in London, United Kingdom. Gavi, the Vaccine Alliance is a public-private global health partnership committed to increasing access to immunisation in poor countries. The organisation brings together developing country and donor governments, the World Health Organization, UNICEF, the World Bank, the vaccine industry in both industrialised and developing countries, research and technical agencies, civil society, the Bill & Melinda Gates Foundation and other private philanthropists. (photo by Paul Hackett/In Pictures via Getty Images)

In Pictures Paul Hackett