RV144: A Phase III HIV Vaccine Trial.

By Patrick Battani
09/25/2009

You may have heard about an HIV Vaccine that is showing some positive results in Thailand. While these are moderate results, there is still some hope that this will further our research efforts. Vaccines are an effective way to help curb the spread of a disease. Although, vaccine research is not new, this is the first time that we have shown some positive progress.

The thought of an AIDS Vaccine came about the time we discovered the disease. In 1984 some of the Nations top researchers and medical power houses said that we would have a vaccine in two years. It is now 2009 and we just hearing about something that could be promising. As of May 2009, AIDS Vaccine Advocacy Coalition (AVAC) reports that there 31HIV vaccine studies currently being conducted world wide.

Many people have wondered why it has taken so long to come up with any type of progress to a vaccine. It is about understanding the difficulty of creating a vaccine for this disease. HIV is a unique virus. Two things make HIV difficult to deal with. One is that HIV can change rapidly; and the other is there are many different forms of this one virus. There are many different subtypes.

Most vaccines teach our body to create an immune response to the disease. So really when we are vaccinated against something, for example the flu, we are really fighting off “reinfection”. Effective vaccines use dead or “life-attenuated” (less potent form) forms of viruses. When HIV dies it no longer has the ability to create the necessary immune response. Also, we are not just going to go around infecting people with HIV, it obviously has some real ethical and safety issues.

To further make things more difficult, most vaccines are created for things that we are only going to come in contact with infrequently; and most vaccines are created for things that we will be infected through the respiratory or gastrointestinal tract. HIV is often contracted through the genital tract. These difficulties have proven to be the downfall of finding a viable vaccine.

Now that you understand a little about the difficulty of creating a virus, let us get back to the “Big News” today: The RV-144 study! RV-144 is a Phase III HIV Vaccine trial that was conducted in Thailand. It is considered the largest human HIV vaccine trial with over 16,000 participants. This study was conducted by the Thai Ministry of Public Health and was partially funded by the U.S. Government through various agencies and U.S. Army Medical Research and Material Command.

The findings of this study were moderate. They found that using the trial vaccine regimen was 31.2% effective at preventing HIV infection. This means that we have evidence that it may be possible to create an effective and safe HIV vaccine in the future.

There are some factors that you should know about this clinical trial. This vaccine was based on HIV strains that are commonly found in Thailand. That means the viral subtypes in the U.S. and Europe may differ from those in the Thailand. This shows that continued research needs to be conducted to make a viable vaccine. Much like the flu vaccine does not cover all forms of the flu; this regimen may not cover all form of HIV.

There is a lot of hope on the horizon about new HIV prevention technology. I will continue to try to update you on the goings on in the world. If you want more information about new technologies being researched, you can check out:

The AIDS Vaccine Advocacy Coalition: http://www.avac.org/
Ministry of Public Health, Thailand: eng.moph.go.th
U.S. Military HIV Research Program: www.hivresearch.org
The International Rectal Microbicide Advocates: http://www.rectalmicrobicides.org/
PrEP Watch: www.PrEPwatch.org

Fauci, A.S. (1996). An HIV vaccine: breaking the paradigms. Proceedings of the Association of American Physicians , 6-13.

U.S. Military HIV Research Program. (2009, September ). FAQ's. Retrieved September 24, 2009, from U.S. Military HIV Research Program: http://www.hivresearch.org/phase3/factsheet.html