The war on AIDS may last decades, the head of the agency UNAIDS warned here, as experts gathered for the biggest-ever conference on a disease that has claimed 25 million lives in a quarter century.
Peter Piot, UNAIDS's executive director, cautioned that painfully-won gains to boost funds and provide anti-HIV drugs for poor people should not delude governments, donors and activists into thinking that the combat was being won.
"We are entering a new phase in the global response. We have got some initial successes, or rather results, but we are facing a move from crisis management to a long-term sustainable response," Piot said in an interview with AFP.
He pointed out that antiretroviral drugs only suppressed HIV, and did not eradicate it. This meant that, in the absence of a cure, patients have to take the powerful medications for their rest of their lives.
"One and a half million people are on antiretroviral therapy in the developing world. And hopefully there will be far more. Twenty, 30 or 40 years from now, we still want them to be alive. Who's going to pay for that?"
Looking back over efforts to fight AIDS since the fatal disease first emerged among homosexual men in California in 1981 and became a global threat, for heterosexuals and gays alike, Piot lamented that many mistakes had been made.
A decade ago, the first anti-retrovirals were introduced in rich countries.
But it took seven years before Big Pharma, prompted by an activists' campaign and competition by low-cost makers of generic drugs, made these lifesaving molecules available at an affordable price in poor countries, where the overwhelming majority of HIV-infected people live.
From 2003, a surge in funding from the United States and other big donors provided the cash to launch the big scale-up.
Now that the money spigot is finally opening up and more people are gaining access to the precious drugs, it is vital for the world not to believe that AIDS is a settled issue, said Piot.
"By any measure, we still have a catastrophe, a crisis. But if now these initial results lead to complacency, that would be a disaster, and we know that keeping anything on the political agenda is difficult."
The 16th International AIDS Conference, opening in Toronto on Sunday, is drawing a record attendance. Around 21,000 researchers, campaigners, health experts and grass-roots workers and representatives from civil society, along with 3,000 journalists, have registered.
According to UNAIDS' estimates, 38.6 million people were living with HIV at the end of last year. The disease claimed 2.8 million lives in 2005, and 4.1 million became newly infected.
Globally, though, the infection rate may have peaked in the 1990s. However some countries and regions, notably Eastern Europe, China and India, are badly vulnerable, while in some parts of southern Africa, a third of adults have the virus.
Piot, a Belgian scientist and doctor, took the helm of UNAIDS on its creation in 1995.
He sketched these goals for the coming years:
-- making so-called second-line drugs available at an affordable price in poor countries when the current first-line treatments encounter resistance, as they inevitably will.
-- ensuring that money flows to enable combat to be sustainable for what could be decades to come.
-- tackling deep-rooted problems, such as homophobia, discrimination against women and AIDS stigma, which provide an ideal breeding ground for an epidemic.
"When you work in AIDS, you see the best and worst in the human species," said Piot.
"You see the most awful rejection and prejudices and even killings and even denial and not wanting to deal with it, and you see also enormous dedication and heroism and activism and people not taking no for an answer. What we have shown is that what seemed to be impossible or a dream has become more and more possible."