An attorney by training, David began working on AIDS issues as a treatment activist with ACT UP and then as Medical Information Director at Gay Men’s Health Crisis, the world’s first AIDS service organization. At GMHC, David was also the Editor of Treatment Issues, a global publication on HIV treatment.

In 1995, David co-founded AVAC to push for greater global investment in AIDS vaccine development and HIV prevention. David also began working with the Rockefeller Foundation to build the International AIDS Vaccine Initiative (IAVI). He served as IAVI’s Vice President for Policy and Public Support where he oversaw the creation of global policy and advocacy programs, as well as IAVI’s regional programs in North America, Europe, Japan and Latin America. Working closely with IAVI’s CEO, David built political support and financial commitments for AIDS vaccine R&D from governments, multilateral agencies, and foundations, totaling more than US$350 million. He also created partnerships and alliances with key institutions, including the World Health Organization, the European Union, the US National Institutes of Health and the Brazilian Government. David also created the IAVI Report, a publication devoted to the AIDS vaccine R&D. David has served on research advisory panels for a number of different organizations including the World Health Organization, the United Nations, and the US National Institutes of Health.

In 2002, David co-founded Global Health Strategies.