Anyone who has travelled widely in sub-Saharan Africa can have been left in little doubt about the catastrophic impact of the HIV/AIDS pandemic. From Uganda to South Africa, thousands of people, including small children, still die every day from the disease. I was devastated to see the suffering caused by HIV/AIDS during a trip to Southern Africa in 2001. And yet, thanks to an unprecedented UN-led global effort, the situation is beginning to improve as more and better drugs become available worldwide and global prevention programmes become more effective. But for a long time economic development was hampered and in some parts of Africa sent into reverse as the virus cut down men and women of working age. In many developing countries, HIV piled a huge new burden on already struggling or inadequate health and social services.

Global public health is a complex and teasing challenge, involving effective use of the full set of policy tools, both national and international. Trade is one of them, and within it, access to essential medicines for all remains the goal. Achieving it requires action across a wide front, from encouraging needed innovation, both medical and technological, to improving systems of health delivery. As the global disease burden evolves, so does the requirement for new and suitable medicines and technologies.