Debunking myths on genetics and DNA

Thursday, August 2, 2012

The beginning of the end. . . Maybe.

"We share a very special moment - it is the moment when an AIDS-free generation is finally in sight." That's what the US president, Barack Obama, said on July 26.

Well, are we?

A colleague a few days ago brought to our attention some stunning figures: according to the CDC, of all HIV infected individuals in the US, only 25% are under treatment and hence have the virus under control. Quite striking if you consider that in Sweden instead 85% of HIV-positive individuals are undergoing treatment. The consequences of such a poor statistic in the US go beyond the lifespan of the single individual: people under antiretroviral therapy have much lower viral loads and therefore a significantly reduced chance of passing the virus to their partners.

I'm not surprised by the CDC numbers, actually. When newly infected, subjects have no symptoms or may feel like they are coming down with the flu. You can live with this virus for ten years without having symptoms. If you don't have health insurance, and you are feeling well, why bother go see a doctor? In the meantime, though, these individuals continue to spread the virus. And the problem doesn't affect the US alone: according to the World Health Organization, less than half of the infected people worldwide are actually receiving treatment.

These were my thoughts as I read the perspective article "The beginning of the end of AIDS?" in NEJM [1]. The authors base their cautious optimism on a few things: mildly positive results on a recent vaccine trial, more effective drugs, and the news of the first patient to ever be cured of HIV. The latter I discussed in this post. The news was indeed exceptional but, unfortunately, gene therapy is not the way to stop this pandemic: 2/3 of people currently living with HIV/AIDS are in sub-saharan Africa, where drugs are still hard to find, let alone extremely costly procedures like gene therapy. And more effective drugs are not going to solve the problem if they remain unaffordable or unavailable to the majority of infected people.

So yes, in the end, it all boils down to funding:
"Global resources have been declining, not growing, in this period of scientific success. This lack of funding is the major point of divergence between optimism and pessimism."
Why invest on HIV?
"Comprehensive economic models predict that making the needed investments in HIV-related efforts will result in cost savings over the long term."
HIV debilitates the immune system. The effects of diseases like tuberculosis, hepatitis and malaria could be reduced if the spread of HIV could be reversed because of the effect the virus has on the immune system. Making antiretroviral treatment available to all infected people is the best strategy: by keeping the viral load under control, drugs effectively lower the rates of mother-to-infant and sexual infections. According to the CDC, about 100-200 infants are born every year in the US with the virus in their body. Adequate treatment during pregnancy and delivery can reduce the rate of mother-to-child transmission to less than 2%.

As we strive to reach out to every infected person on the planet, funding must not stop for research. A vaccine is the most affordable and most effective way to stop the pandemic and we have to keep pushing in that direction. My supervisor gave a talk last week in which she outlined where we are in terms of vaccine research. She opened the talk remembering how the first vaccine was discovered: the English physician Edward Jenner (1749 - 1823) rubbed pus collected from blisters milkmaids received from cowpox on his gardner's eight-year-old son. He then exposed the boy to pox, twice, and noticed that they boy didn't develop the disease. The audience was of course horrified when my supervisor mentioned the sacrifice of the little boy, and yet when she went on describing how long and, most importantly, how much money is needed to develop and test a vaccine, a girl in the audience raised her hand and asked: "Well, maybe you can't take an eight-year-old boy, but wouldn't you be better off testing the vaccine on yourself?"

We can't, of course. The gardner's boy got lucky, but things don't always go well. The field still hasn't forgotten the failure of the Merck vaccine in 2007, the trial that was halted after the experimental vaccine was found to make some subjects more susceptible to infection. The FDA has a set of very strict regulations on vaccines. They need to be stable, in other words, one has to show that they don't change after they've been grown for several generations in cultures. They have to be attenuated, and remain so after several generations. Vaccines are then tested on mice, first, then monkeys, then, years later, on humans in several phases that take time, money, and then more time and more money. And yet what we really cannot afford is to stop pushing the research forward.
"Every country must develop more effective ways to reach key affected populations and to apply the tools that we know work, if we are to make significant advances."
So, Mr. President, I hope you are right. But I also hope you will keep funding our efforts.

[1] Diane Havlir, & Chris Beyrer (2012). The Beginning of the End of AIDS? New England Journal of Medicine : 10.1056/NEJMp1207138


  1. Thanks for the post ... now I really see the value of the recent addition of HIV screening to preventive services, e.g.:

    "Access to HIV Testing for Women Increases Thanks to Affordable Care Act"


Comments are moderated. Comments with spam links will be deleted and never published. So, if your intention is to leave a comment just to post a bogus link, please spare your time and mine. To all others: thank you for leaving a comment, I will respond as soon as possible.