Leading article: Ignorance and denial still conspire to prevent action

On 5 June 1981, the US Centres for Disease Control and Prevention reported the first cases of what would become known as Aids. Twenty five years later, the disease has killed 25 million people, infected 40 million more and created 15 million orphans. The rate of infections peaked in the late 1990s, UNAIDS reported yesterday, but the number of people living with HIV is still rising.

The statistics are numbing, and many remain numbed by them, including world leaders still awakening to the reality. For years, the inadequate response to Aids allowed the pandemic to expand unchecked. Not until 2001 did the fight against Aids become a global priority, when 189 countries declared it a worldwide emergency.

Five years on, as the UN meets in New York today to review the situation, there are some signs of progress. There is more cash - up from less than $1bn in 1999 to more than $8bn in 2005 - nearly 1.5 million people in developing nations are getting anti-retroviral drugs, and six of the most heavily infected African countries have cut the spread of HIV among young people.

A key contributor to this achievement has been the Global Fund, the Swiss foundation established by the G8 nations in 2001, which has not only raised billions for the fight against Aids, tuberculosis and malaria, but also distributed the funds in record time. It was the beneficiary of The Independent's RED issue edited by the rock star Bono earlier this month. But the challenge is still immense and the response to it still inadequate. The epidemic is growing more rapidly than the world is working to stop it, and while in some countries the spread is slowing, in others it is accelerating. An estimated $20bn will be needed annually from 2008.

The US President's Emergency Plan for Aids Relief, though unlocking $15bn-worth of funds and boosting treatment, has had a disastrous impact on prevention, with its emphasis on abstinence and resistance to condoms. Family planning organisations across Africa have lost funding after failing to comply with strictures preventing the promotion of condoms.

Hopes were raised this month that Pope Benedict XVI was poised to ease the Catholic church's opposition to condom use for married couples where one partner was HIV infected. This would offer crucial protection to women. In every region of the world the proportion of women being infected is increasing. The lack of control of women over sexuality and the absence of female-controlled methods of protection is a key reason behind the growth of the epidemic. Microbicides - gels or creams for women to protect themselves - are under development, but will not be available before 2010, the UN says. Beyond that, wider HIV testing, sex education and reproductive health care for girls and women are vital elements of the campaign against Aids.

There are other glaring gaps. Fewer than one in five of those who inject drugs and less than half of sex workers receive help - clean needles and condoms - to avoid HIV infection. Less than one in 10 gay men received any type of HIV prevention service in 2005. Such services are vital in regions such as Russia, where the virus is poised to break out of the marginal high-risk groups into the general population. But ignorance and denial conspire to prevent action. As Peter Piot, executive director of UNAIDS, observes: 25 years on, nations still think of Aids as a crisis in need of a quick fix. Not true: it is a massive long-term problem that demands the kind of response we give to preventing financial meltdown or curbing nuclear weaponry. Aids now kills more adults than all today's wars and armed conflicts combined. But it is still not generating a commensurate response.