The evolving HIV/AIDS response and the urgent tasks ahead.

AIDS continues to outpace the science, financing, prevention, and treatment efforts of the past quarter-century. There have been different epochs along the evolutionary timeline of the global AIDS response, from the discovery of HIV to the threat posed by the current economic crisis. This timeline serves as a reference to how we have arrived where we are today, in the hope that understanding our past will help us set the course for a more efficient and effective future response.