While HIV/AIDS and infectious disease control absorbed about 20 per cent of ODA commitments in the 1990s (12 and 8 per cent, respectively), these programmes accounted for 51 per cent of all commitments in 2005-2006 (35 and 16 per cent, respectively). Firstly, fighting against certain diseases (especially contagious diseases) is a global public good, and it therefore requires global and effective responses. Secondly, focusing on a specific disease can mobilize public opinion and resources in a more effective way.