As we commemorate this year’s World Aids Day on Saturday, we are called upon to be leaders in the fight against Aids. Where there is strong and committed leadership, the response is more effective. The new estimates by Joint United Nations Programme on HIV/Aids (UNAIDS) and World Health Organization (WHO) on HIV prevalence are encouraging. The percentage of people living with HIV has leveled off and the number of new infections has fallen. This is due in part to HIV prevention and treatment programmes. However, Aids still remains a leading cause of death worldwide with more than 5,700 people dying everyday. During the next 24 hours, more than 6,800 people will be infected. Now is the time to strengthen prevention efforts and reduce the impact of Aids. HIV prevention remains the first line of defence and must be accelerated alongside treatment. Together, we must take action towards universal access to prevention, treatment and care. Donors can be leaders by closing the resource gap, and helping the international community to double funding for Aids by 2010 to meet the promise made by governments in the United Nations General Assembly. Health-care providers can be leaders by integrating HIV prevention and sexual and reproductive health programmes and delivering prevention messages to all. This is especially important for young people among whom half of all new HIV infections occur. Young people can lead the way by advocating for their specific rights and needs. Young men and women can introduce new approaches to HIV prevention and are natural partners in the fight against Aids. It is also time to promote the leadership of women. To reverse the spread of HIV, we must tackle the gender inequities that fuel the disease, and ensure that women lead an effective response. Men and boys, too, can take the lead by promoting equality in relationships and providing positive role models within families, partnerships and communities. Governments must be leaders by investing in comprehensive national programmes focusing on HIV prevention, with clear national targets and broad-based support. There can be no effective response to HIV without committed leadership at the highest level. And critical to success is the active involvement of people living with HIV and Aids. It is their courage, honesty and leadership that help keep political leaders and elected officials accountable for promises made and progress over the course of time.As the world marks the Aids Day, UNFPA recommits to leadership in HIV prevention. Together, we must keep the promise and take the lead to stop Aids. Thoraya Ahmed Obaid is the Executive Director of UNFPA