In this entry in the Huffington Post’s “Impact” blog, Orin Levine of the Department of International Health at Johns Hopkins Bloomberg School of Public Health and executive director of the International Vaccine Access Center (IVAC) recounts recent progress in expanding vaccine access to the world’s poor and highlights current and recent vaccine access projects led by the GAVI Alliance and IVAC. He concludes, “At their best, vaccines are tools for social justice that eliminate health inequities — but only if all people, everywhere have access to these life-saving innovations. … Only with universal access will we have truly harnessed their power” (12/9).