Drugmaker Pfizer Inc. has agreed to provide hundreds of millions of doses of its lucrative vaccine against pneumonia and meningitis at a fraction of the usual price for young children in poor countries. The deal to provide 260 million shots of its Prevnar 13 vaccine for a few dollars each is Pfizer's third agreement under an innovative program through which pharmaceutical companies, governments, health groups and charities collaborate to bring poor countries a long-term supply of affordable vaccines against deadly diseases…The [Global Alliance for Vaccines and Immunization] has estimated the pneumococcal vaccines could save up to 1.5 million lives by 2020…