Nina founded Spark Street in 2016. Her leadership positions include Managing Director for Policy and Performance at Gavi, the vaccine alliance, where she led Gavi's work in strategic planning, policy development, market-shaping, performance management, and monitoring and evaluation; Principal Advisor and Acting Chief of Health at Unicef, overseeing their health programs in over 150 countries; and Director of Global Public Health for the Open Society Institute. During the COVID-19 pandemic, she established USAID's COVID-19 Vaccine Access and Delivery Initiative and served as its first director. Nina holds a BA from Harvard, an MPH from Columbia and PhD from Witwatersrand University. A lifetime member of the Council on Foreign Relations, a Senior Scholar at Georgetown University's O'Neill Institute for National and Global Health Law, a Principal Visiting Fellow at the United Nations International Institute for Global Health, and a Lancet Commissioner for gender and health.