Despite years of strong progress in reducing HIV at the global level, success in different countries and regions varies as the HIV epidemic has peaked and declined at different times, and depending on access to, and quality of antiretroviral therapy (ART), and other care.
The new GBD estimates show a slow pace of decline in new HIV infections worldwide, with a drop of just 0.7 per cent a year between 2005 and 2015 compared to the fall of 2.7 per cent a year between 1997 and 2005.
Improvements and updates in GBD's data sources and methodology indicated that the number of people living with HIV had been increasing steadily from 27.96 million in 2000 to 38.8 million in 2015.
Annual deaths from HIV/Aids had been declining at a steady pace from a peak of 1.8 million in 2005, to 1.2 million in 2015, partly due to the scale-up of ART.
Further, the proportion of people living with HIV on ART increased rapidly between 2005 and 2015, from 6.4 per cent to 38.6 per cent for men, and from 3.3 per cent to 42.4 per cent for women.
Yet, most countries were still far from achieving the UNAIDS 90-90-90 target of 81 per cent by 2020.
While the annual number of new infections has decreased since its peak at 3.3 million per year in 1997, it has stayed relatively constant at around an estimated 2.5 million a year worldwide for the past decade.
"Although scale-up of antiretroviral therapy and measures to prevent mother-to-child transmission have had a huge impact on saving lives, our new findings present a worrying picture of slow progress in reducing new HIV infections over the past 10 years", said the study's lead author, Dr Haidong Wang, of the University of Washington.
Development assistance for HIV/Aids is stagnating and health resources in many low-income countries were expected to plateau over the next 15 years.
Therefore, a massive scale-up of efforts from governments and international agencies would be required to meet the estimated $36 billion needed every year to realise the goal of ending AIDS by 2030, along with better detection and treatment programmes and improving the affordability of antiretroviral drugs.