As the HIV/AIDS epidemic continues its relentless regional and global spread, a visible shift is taking place from the prevailing focus on treatment and care services of the past few years towards prevention strategies and interventions aimed at reducing further spread of the virus.

According to one leading expert speaking in the plenary sessions at the 7th International Congress on AIDS in Asia and the Pacific (ICAAP), mainstream HIV prevention strategies - such as behavioural change programmes, and condom or clean needle promotion - are insufficient to stop HIV in its tracks, even though they are crucial short- to medium-term solutions.

In the long term, "the only historically proven tools to end viral epidemics are vaccines," said Dr Seth Berkley, President and CEO of the International AIDS Vaccines Initiative (IAVI). But an AIDS vaccine will not happen unless given a new level of attention and priority, he added.

In accordance with the UNGASS (UN General Assembly Special Session) Declaration of Commitment on HIV/AIDS of 2001 and the Millennium Development Goal (MDG) on HIV/AIDS (MDG6), halting and reversing the spread of HIV/AIDS by 2015 should be possible. With current prevention strategies regarded as only partially effective - and the currently available treatment options facing uncertain levels of future resistance - vaccine development might offer the only plausible alternative. It might also provide scientific insights that could open the door to potential new treatment options.

Basic vaccine research can help increase understanding of the immune system responses that are needed to protect against the virus, for example. If they are better understood, this may pave the way towards new immune-based therapies for those already infected to delay or prevent AIDS-related conditions, including opportunistic infections (OI).

There are currently more than 30 candidate HIV preventive vaccines being tested in some 20 countries around the world. These are small-scale human clinical trials. Of the four countries in the Asia and the Pacific region, taking part in these trials, Thailand is in the forefront of the region's vaccine research and development (R&D) efforts. The other three - India, China and Australia - have not carried out the kind of large-scale human clinical trials that Thailand has undertaken. Dr Berkley praised Thailand for its "pragmatism and understanding that it is critical to move forward". The Kingdom recently completed the first-ever AIDS vaccine efficacy trial with another being planned. On the road to an effective vaccine, more large-scale AIDS vaccine trials of this kind need to be carried out in countries with relatively high HIV incidence rates, in order to ensure that trial results are valid.

There are several reasons why R&D efforts are lagging in the region. Vaccine development not only faces scientific challenges, but also requires stable public-private partnerships (PPPs), regulatory reforms and community vaccine preparedness.

The clinical and scientific challenges boil down to years of research and trials, many of which will likely be rendered irrelevant as some trial outcomes prove fruitless. Furthermore, a sustainable trial operation requires a long-term collaborative and coordinated effort at various institutional and policy levels.

"We need to look at the challenges globally," observed Dr Berkley, who claimed that with global spending on AIDS vaccines accounting for less than 1% of global spending on all health product R&D, it is hard to foster a conducive environment in this field especially in the resource-limited settings generally found in this region.

The pharmaceutical industry is the only sector with a track record in developing, manufacturing and distributing vaccines on anything like the scale an HIV vaccine would demand. According to Berkley, it is crucial "that we engage and commit the industry to making them [future vaccines] available with sustained financing."

That will also require assessing what companies from each region of the global south possess in terms of technologies and going beyond national efforts to foster serious inter-country political and scientific partnerships.

"We need to help build the capacity of developing countries to conduct AIDS vaccine trials where regulatory expertise and HIV/AIDS-related healthcare infrastructure and services are weak or lacking," added the IAVI head.

In addition to political resolve at a national level, a universal regulatory framework that includes advanced purchase commitments, tax incentives and intellectual property protection is essential to create both the 'push' and 'pull' mechanisms for the sustainable development and delivery of HIV vaccines.

Arguably even more importantly, local communities in affected countries play a crucial role in this overall effort. A viable environment for vaccine research and trials has to first be fostered by encouraging voluntary HIV testing; counselling and study participation. This can be encouraged by raising awareness; and ensuring that trial facilitators fully consider the ethical aspects, such as informed consent, into their trial implementation. India is a leading example of how so-called 'community vaccine preparedness' is being enhanced, with a second HIV vaccine clinical test currently underway in the country.

HIV vaccines should not be seen as competing with on-going HIV/AIDS prevention and treatment efforts, but rather an expansion of currently available options. After all, vaccines have been successfully developed and used against other life threatening diseases such as yellow fever, measles and polio.

Nevertheless, when the topic of preventive HIV vaccines surfaced at the ICAAP conference, some participants aired doubts about how long it will take before effective results are seen.

"People are dying every day. I am HIV positive and what I need now are drugs to keep me alive. I may be dead by then," implored a participant from India.

In light of the epidemic that continues to spread at a breakneck speed, Dr Berkley simply concluded, "the end game is vaccine."