SEARCH FOR A WONDER VACCINE

       "To successfully develop a vaccine takes a very long time,a huge budget and a long-running procedure ... Vaccine development is not always done for commercial purposes. So we researchers desperately need strong support from all partiesinvolved PUNNEE PITISUTTITHUM
       Ajourney of a thousand miles all begins with a single step, and so does the journey of Punnee Pitisuttithum."The development of an HIV/Aids vaccine is like a hurdle race. There are a number of barriers that we researchers must jump across. And in this race, to reach the finish line is not a piece of cake," said Punnee, head of the Department of Clinical Tropical Medicine, Mahidol University.
       For more than 10 years, the 52-year-old researcher has been devoting her time and energy working on HIV/Aids vaccine trials. Her job is to test preventive serums over and over to see whether any of them can work against the particular HIV strain found in Thailand. After a considerable amount of trial and error,the effort Punnee along with her team invested eventually paid off when the result of the HIV/Aids vaccine trial recently carried out was announced.
       The result of the trial shows that the vaccine has 31.2 percent efficacy in preventing HIV/Aids infection.In other words, it appears to be able to reduce the chance of catching the virus by around one-third in tested volunteers. Yet it cannot lower the level of virus in the blood in infected cases.
       But even though the effectiveness of the new vaccine is yet to reach the 50 percent efficacy rate needed to apply for a vaccine licence, and that the vaccine seems to not be powerful enough, the result can still be considered an important scientific breakthrough. The experimental project, according to Punnee, does indeed give new hope in the HIV/Aids vaccine research field and at the same time paves the way for the development of more successful anti-HIV drugs in the future.
       "During the past five to six years, apart from testing the HIV/Aids vaccine, we [research team]have also been working to empower the community through vaccine trials. We have raised awareness and created a better understanding regarding the importance of HIV/Aids prevention. Volunteers that took part in the trial along with other people in the community have become a part of the project and have begun to have a sense of belonging. We have created networks among volunteers and established a volunteer club. At the same time, we have also trained our staff so that they meet international standards.'
       "This way, we have improved our research infrastructure, boosted capacity building and prepared groundwork for future studies which, to me, is as important as the trial itself," commented Punnee,who is also chief of the Clinical Infectious Diseases Research Unit.
       Graduated from the Lady Hardinge Medical College,Delhi, India, Punnee has been working with the Vaccine Trial Centre, a clinical facility founded within Mahidol University's Department of Tropical Medicine, for more than 20 years. Her main responsibility is to examine the safety and efficacy of vaccines sent from vaccine manufacturing companies in other countries and to also check, analyse and confirm whether they are safe to use in Thailand. So far she has experience in clinical vaccine trials for cholera,polio and cervical cancer.
       According to the professor, the HIV/Aids vaccine trials in Thailand first started in 1994, after the spread of the epidemic in the early 1990s. At that time, a team of researchers only attempted to use one vaccine that could stimulate just one arm of the immune system. Unfortunately, it failed.
       "In the trial we conducted earlier, we used an HIV/Aids vaccine called Aidsvax, which could create antiviral immunity only in human blood. But it didn't succeed. The vaccine was not able to prevent the HIV/Aids infection. So we came up with a new regimen.This time we created immunity for both human blood and human cells," recalled Punnee of how the recent HIV/Aids vaccine trial was initiated.
       The vaccine clinical trial, referred to as RV 144,was carried out under the concept of "prime-boost"combination, the scientist explained. Simply speaking,RV 144 tested two vaccines. The first, Alvac HIV or the "prime", enabled the body to make immune defences to target cells invaded by the virus before the infection could spread out of control. The second,Aidsvax B/E or the "boost", stimulated the production of immunity in the blood. The vaccine combination,Punnee remarked, was based on HIV strains that commonly circulate in Thailand.
       Alvac HIV was developed by Sanofi Pasteur, the vaccine division of French-based drug manufacturer Sanofi-Aventis, while Aidsvax B/E was originally developed by Genetec Inc and is now licenced to Global Solutions for Infectious Diseases.
       The trial, Punnee went on, was designed primarily to test the ability of the vaccine formula to prevent HIV/Aids infection, as well as its ability to reduce the amount of viral load of those who became infected.
       RV 144 involved 16,402 HIV-negative male and female volunteers aged 18 to 30. Having lived in Rayong and Chon Buri province, these heterosexual Thai candidates were at average risk of contracting the HIV/Aids.
       All participating candidates were divided into two groups: one group received the prime-boost vaccine regimen and the other was administered placebos.Vaccines were injected into volunteers over the course of six months. After that, the test subjects were required to have a follow-up blood test once every six months for the next three years.
       Prior to their participation in the trial, all candidates were notified of and consented to the potential risks associated with receiving the experimental vaccine combination. Throughout the study period, they also received counselling on HIV/Aids prevention.
       RV 144 began in October 2003. In total, it took about six years for the trial to be fully completed.And this, according to Punnee, was the first successful prime-boost vaccine trial in the world, which signifies that the development of a safe and effective vaccine against one of the world's most dangerous pandemics is still possible.
       Involving such a large number of volunteers being tested, RV 144 was also Thailand's first communitybased and the world's largest HIV/Aids vaccine trial ever conducted, added the professor.
       "Right now there are approximately 600,000 Thai people living with HIV/Aids infection. And each year there are about 16,000 new cases of HIV/Aids infection reported in Thailand. The vaccine will therefore be like the light at the end of the tunnel for the world population," said the researcher.
       As the HIV/Aids vaccines were manufactured in Western countries, the next question is:"Then why was the vaccine trial performed here in Thailand?"
       "Testing a vaccine in countries other than the particular one that will use the vaccine is ethically wrong," Punnee explained."If we, for example, want to use the HIV/Aids vaccine in Thailand, it is critical that we test it here to see whether it works with the particular strain that spreads here. And it's the same with this [RV 144] trial. If other countries wish to use this vaccine regimen, they have to test and further develop it in their respective countries, too."
       "Admittedly, Thailand itself is not yet capable of creating such vaccines. And we have absolutely no idea as to when we will be ready to do so. But carrying out the trial and having the HIV/Aids vaccines tested here in Thailand will enable our country to have negotiating power in terms of the vaccine price to be sold here. With our participation in the trial run, Thais will have vaccines that are cheaper and more affordable," she added.
       The future of vaccine development in Thailand,according to the vaccine analyst, looks quite promising.Since the Avian influenza outbreak several years ago, Thailand has been on alert and started building and improving the country's potential in producing vaccines to shelter its people from illnesses. The Ministry of Public Health is now therefore working actively on its plan to set up a plant to manufacture vaccines both for use and for study. One of the country's most significant threats is, however, the lack of scientists who are capable of developing knowledge and expertise needed for vaccine production.
       "Thailand has come a long way from where it first began in terms of vaccine research and development.During the past 20 years, our vaccine clinical trials have met international standards. Even so, we still have quite a long way to go because to successfully develop a vaccine takes a very long time, a huge budget and a very long-running procedure. Successful laboratory research, for instance, does not necessarily mean that the vaccine will work well for everybody.More studies are essential to ensure that the vaccine will be safe to use.
       "Vaccine development is no easy task. And it is not always done for commercial purposes. So we researchers desperately need strong support from all parties involved," Punnee noted.
       Now that the result of the RV 144 HIV/Aids vaccine trial has been disclosed, Punnee and her team are well aware that a lot more work, studies and challenges lay ahead.
       Yet the researcher considers the recent vaccine trial as the first step towards success. She fully hopes that a safe and highly effective HIV/Aids vaccine will one day be accessible to people not just in Thailand but also around the globe.
       "The ultimate goal of all vaccines is to function as a preventive measure against a specific disease prior to a person being infected. So my highest hope for the HIV/Aids vaccine is that some day in the future the young generation will be eligible to receive the vaccine, especially before their first sexual experience.In the meantime, we researchers have a lot of work to do. And the result of our previous trial will be a stepping stone to our path towards developing a successful vaccine."