It is no surprise that Thailand has held the largest ever trial of an HIV vaccine. The South East Asian country has long been at the forefront of the battle against HIV and Aids.
Thailand has worked hard to fight HIV/Aids but it is still a key problem
"I did this for others," said 33-year-old electrician Thanad Yomha. "It's for the next generation".
Thanad was one of more than 16,000 Thais from the provinces of Chonburi and Rayong who volunteered to take part in the trial, which was run jointly by the Thai government and US military.
The researchers had sought HIV-negative men and women between the ages of 18 and 30 years old who were at an average risk of infection.
They wanted to test a combination of two vaccines, ALVAC and AIDSVAX, which on their own had previously not worked.
From 2003 to 2006, half of the volunteers received the vaccine, and the other half a placebo. Those taking part never learnt which one they had been given.
After that, the volunteers received an HIV test every six months for the next three years.
Of those who took the dummy injection, 74 of 8,198 volunteers became infected, compared with 51 of 8,197 who took the vaccine.
All volunteers had received counselling on how to prevent infection throughout the trial, and those who became infected were given free access to HIV care and treatment. Two people have since died.
Rayong farmer Aree Kamphonrat had six jabs over the course of the trial, and says she has no regrets. Many people in her village took part.
"I wanted to help all countries to fight HIV and also I wanted children not to get infected by HIV," the 32-year-old was quoted by AFP as saying.
The results of the trial show that the vaccine lowered the rate of HIV infection by 31.2% compared with the placebo.
Although the results are modest and need further study, the trial has been hailed as a major scientific breakthrough by the medical world because it is the first time a vaccine has been shown to be able to prevent HIV infection.
The US military has a long-standing relationship with the Thai authorities in the fight against HIV and Aids.
It goes back to the early 1990s, when American army researchers helped to identify and isolate virus strains that could be used to develop vaccines.
Doses of the vaccine and placebo were given to volunteers over three years
At that time, Thailand was working hard to counter gloomy predictions that as many as four million of the 65 million population could become infected by 2000.
Thailand's booming sex industry and its popularity among foreign tourists had fuelled fears of a major epidemic.
But a massive Aids education and prevention campaign by the government in the early 1990s is credited with doing much to stop that from happening.
It was spearheaded by outspoken senator Mechai Viravaidya, who became known as "Mr Condom" for his efforts to promote safe sex, especially among prostitutes.
Brothels began to use condoms, anti-Aids messages went out on radio and television as well as in schools, hospitals, police stations and courthouses.
The result was a dramatic decline in the spread of HIV across the country, prompting the World Bank to describe it as one of the few examples of a successful national Aids prevention programme.
By 2003, the annual number of new HIV cases had fallen to 19,000 - down from 143,000 at its peak in 1991.
In 2005, Thailand took on the major pharmaceutical companies by announcing it intended to pioneer production of its own, much cheaper, anti-retroviral drugs.
This, it said, would enable every one of the estimated 500,000 HIV-positive people in Thailand to receive treatment.
Though Thailand has never experienced the levels of infections that were once predicted, a resurgence is possible, say experts.
Drug users who inject and the rise in unprotected casual sex, particularly among younger people, remain causes for concern.