Tuesday, September 29, 2009

A Different Vaccine

This should not be a long post as there is not too much to report or explain. The reason I want to address the recent “breakthrough” in HIV (human immunodeficiency virus) vaccine research is to bring attention to the field.

HIV was first discovered the year I graduated from high school – 1983 -though it had been in existence since 1981. It took many years to figure out what we were dealing with and much misinformation and fear spread through the country and the world. HIV is linked to AIDS, acquired immune deficiency syndrome, which is terminal. Many people who were infected with HIV contracted AIDS and died quickly, in the early years.

Much research and time has gone into this disease, at first the funding seemed to come from celebrities more than governments. When we learned that it wasn’t a “gay” disease the research got a little more investment and attention, which it deserved regardless of the population it affected most. People live long, productive and even healthy lives with HIV in some countries and in some conditions (access to care!). In other countries it continues to spread unheeded and no cure nor HIV vaccine has been found.
How very different this is than say, oh, H1N1.
Bing, bang, boom, expect your shot next month.

In the chart (right) for the US you can see that we have less new cases, but larger numbers of persons who are living with the disease.

Some 65 million persons world wide have been infected with the virus and 25 million or more have died from it. The disease is not evenly spread through the world with many more cases being found in sub Saharan Africa than the US or UK.

We have learned a lot about the transmission of the disease and our safe sex campaigns have had a great impact especially in countries were condom use is considered “the norm.” Some cultures and some political platforms have thwarted these efforts. For example, in some countries it would be a great insult to a man to ask him to wear a condom and in others, funding for programs has been tied to (impractical) abstinence only programs.

Now my little history lesson has made my post longer than I had anticipated and I must get to the point.

We have had many trials of vaccines that have had no impact on preventing the transmission of HIV or protecting a person from it. Just this week however, scientists in Thailand report positive results from a United States funded study.

The study involved a combination of two previously ineffective vaccines and was given to approximately half of 16,000 volunteers. The others received placebos. The two meds work differently. One introduces a deactivated virus that carries three HIV genes into the body. The body recognizes those and in theory, creates T cells that will find and destroy the virus. The other drug introduces a protein of the HIV virus into the body so that the body will make antibodies that can neutralize that protein, thus stopping an infection.

Together these medicines had a protective effect in 31% of the experimental group. Or to say this right, there were 31 percent less infections in that group than in the group that did not get the vaccine. There were infections in both groups during the three year study.

I often wonder who would volunteer for this and what do scientists do, tell them to have unprotected sex with an infected person? As best I understand this study, the persons were put in their groups and all were advised on safe sex practices and then left to do what ever it is they did.

The researchers had hoped that if the vaccine did not stop the virus it would at least lower the viral load. That did not happen in the study. Those infected had what ever the usual potency of virus is. Also know that HIV has different strains just as our flu does. This is by far the end of the story, but it certainly offers hope.

The scientists now have to determine by what mechanism the vaccine did work so they can duplicate it. There is some irony that our country paid for the study in another country by a vaccine made in part by a French company and in part with a San Francisco non profit. Still the whole world will benefit from results.

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