According to a new report by the World Health Organization (WHO), UNAIDS and UNICEF, only 28% of the world's poor with HIV have access to the antiretroviral drugs that could save their lives.
The report warns that the United Nations' target of universal access to HIV/AIDS prevention and care programmes by 2010 will fail unless the many obstacles are removed.
WHO director general Margaret Chan says more ambitious national programmes, greater global mobilisation and increased accountability are needed to achieve success.
The report says even though substantial, ongoing progress has been made towards improving treatment and diagnosis of people with HIV, there is still a long way to go.
Although by the end of 2006, 2,015,000 people in low and middle-income countries were receiving antiretroviral drugs to control their HIV infection, which represents a 54% increase in one year, 7.1 million people in those countries could benefit from the drugs.
The figures fall short of the WHO aim of getting antiretrovirals to 3 million needy people by the end of 2005.
The report found that 1.3 million HIV patients in sub-Saharan Africa are now receiving the drugs which represents a 28% coverage rate in the area compared with just 2% in 2003.
The lowest access rate, a mere 6%, was in the North Africa and the Middle East and only 11% of pregnant women with HIV are receiving the drugs that could prevent them passing the virus to their baby.
The report says the prevention of mother-to-child transmission needs to be made a top priority.
The drop by 20% last year in the prices of front-line drugs in the world's poorer countries means some drugs are now less than half the price they were in 2003.