Access to the expensive, effective treatments is still limited
Falling prices and increased testing have led to a marked rise in the number of people in the poorest parts of the world receiving treatment for HIV.
The number of people on antiretrovirals had risen by 1m by the end of 2008, a 36% increase from the previous year, the World Health Organisation reports.
But despite the progress, less than half of those needing treatment get it.
The majority of pregnant women still go untreated, and their infants are infected via "vertical transmission".
Nevertheless testing of pregnant women is continuing to rise in line with rates overall.
Testing is the gateway to treatment, and in many areas facilities providing this service increased by about 35%, noted the Towards Universal Access report which looked at 158 countries.
"An Aids free generation is no longer an impossibility - the elimination of vertical transmission is in sight," said Jimmy Kolker, head of the HIV/Aids division at UNICEF.
Just the same
Drug prices have also fallen by between 10% and 40% - the result of a combination of a factors, including greater co-operation by the pharmaceutical companies and the prevalence of generic drugs.
There is currently momentum behind the establishment of a patent pool, which would allow the creation of cheap copies of drugs and would be one way of getting newer and more effective second-line treatments into the developing world.
The report highlighted the problems of access to these treatments: the majority of people who are being treated in the developing world receive a combination of cheaper, older drugs which are barely used in the West because of their sometimes serious side-effects.
Three years ago, the World Health Organisation recommended a shift away from these medications to less toxic ones based on either Zidovudine or Tenofovir.
But these remain significantly pricier than the older ones: currently the Tenofovir-based combination is more than twice as expensive as the traditional combination.
But by current reckoning, at least 5m people with HIV do not have access to even the most basic treatment.
The pace of new infections also continues to outstrip the number treated: for every one person being put on a therapy regime, three people contract the disease.
The report highlighted particular concerns about access to high risk groups, such as gay men and sex workers. It noted that as many as 6m drug users are infected worldwide, but less than 40% are reached by HIV prevention programmes.
There are also concerns that recession will hit the international funds flowing into countries where the need is great.
"This report shows tremendous progress in the global HIV/Aids repsonse," said WHO director general Margaret Chan.
"But we need to do more. At least 5m people living with HIV still do not have access to life-prolonging treatment and care.
"Prevention services still fail to reach many in need. Governments and international partners must accelerate their efforts to achieve universal access to treatments."