There was cautious optimism in Vietnam last month when a trial HIV vaccine in Thailand appeared to provide some protection against the deadly virus.
Vietnam country director of UNAIDS Eamonn Murphy said he and his Vietnamese colleagues were confident that a fully effective vaccine could be developed in the future.
However, he qualified that optimism: "I do not see an end in sight."
Released on September 24, the results of the three year trial found that the chances of catching HIV, a retrovirus that causes AIDS, were 31.2 percent less for those who had taken the vaccine. Among the heterosexual Thai volunteers, 74 people who did not get the vaccine were infected, compared to 51 percent of the vaccinated group infected.
"Ultimately we still need to rely on comprehensive HIV prevention," Murphy said.
The trial was the first time in the virus's 28 year history that a potential vaccine had shown any efficacy but the call for celebration was only momentary, as the limited effectiveness of the vaccine was a sobering reminder of the need for vigilance.
“The numbers are small and the difference may have been due to chance, but this finding is the first positive news in the AIDS vaccine field for a decade,” said Dr. Richard Horton, editor of the Lancet medical journal in a BBC report.
Michel Sidibé, Executive Director of the Joint United Nations Program on HIV/AIDS (UNAIDS), said governments and stakeholders should "prepare today for tomorrow" when a vaccine becomes available. "We must not allow cost to deter people from access to a vaccine."
Sidibé also asked civil society to keep breaking down the social barriers to vaccine uptake.
Murphy added that it was too early to talk about introducing a vaccine and many more studies needed to be done.
"We have seen improvement in prevention in Vietnam and that's what we need to focus on."
There were major challenges ahead, Sidibé said in a statement, adding that less than half the people who need treatment have access and a lot has to be done to strengthen HIV health services and make antiviral drugs and a vaccine – when it comes – affordable for everyone.
Talking of those challenges, Murphy said there was a long way to go reducing stigma and discrimination in Vietnam before high risk individuals would access a vaccine. He added that governments should provide more funding to find a vaccine.
Murphy said official figures showed that at the end of March 2009, more than 42,000 people "that we are aware of" had died in Vietnam from HIV or AIDS related illnesses.
"But this figure is probably too low because many people would not want to identify that their family members have died of AIDS due to the stigma and discrimination associated with this," he said.
"The challenge in Vietnam is that the epidemic is concentrated among groups like injecting drug users, sex workers and their partners and men who have sex with men (MSM) and you can not identify people easily in communities who may be at risk."
UNAIDS figures on the epidemic show that 30,996 people are currently living with AIDS in Vietnam and 243,000 have HIV. Every province is affected with concentrations in high risk groups in the cities. One rehab for drug addicts in HCMC reported that two-thirds of their clients were positive for the virus while an NGO working in the central provinces said one third of injecting drug users there tested positive.
Between 2003 and 2006 more than 16,000 Thais from the provinces of Chonburi and Rayong volunteered to take part in the trial, which was run jointly by the Thai government and US military.
The researchers tried a combination of two vaccines, ALVAC and AIDSVAX, each of which on their own had previously not worked.