HIV evolution: individual vs. population

By iayork | Published November 30, 2010

Worldwide HIV/AIDs Epidemic Statistics

(We are in the process of selling one home and buying another, while at work I just finished organizing a course on biosecurity for an international group. In the upcoming week I’m traveling to a conference in Washington. To say nothing of the Thanksgiving holiday. All this means short and scarce updates for a little while.)

We know that the immune response to HIV forces the virus to evolve at great speeds, so that the viral targets of the immune response change and become at least temporarily invisible. We also know that the specific targets are different for almost every infected person. So although you have rapid evolution in each individual, what does this mean to overall evolution of the global population of HIV?

The several dozen CTL epitopes we survey from HIV-1 gag, RT and nef reveal a relatively sedate rate of evolution with average rates of escape measured in years and reversion in decades. For many epitopes in HIV, occasional rapid within-host evolution is not reflected in fast evolution at the population level.¹

(My emphasis) This is a modeling study (though it did look at real-life data to some extent), but their conclusion is consistent with larger-scale population studies as well; see my previous post here and links therein.

Fryer, H., Frater, J., Duda, A., Roberts, M., , ., Phillips, R., & McLean, A. (2010). Modelling the Evolution and Spread of HIV Immune Escape Mutants PLoS Pathogens, 6 (11) DOI: 10.1371/journal.ppat.1001196[↩]

This entry was posted in Evolution, Science, Virology and tagged HIV, Immune evasion. Bookmark the permalink. Follow any comments here with the RSS feed for this post. Both comments and trackbacks are currently closed.

5 Comments

Best

Posted December 8, 2010 at 4:10 pm | Permalink

It would interesting to know what humans have had the capability to defeat the virus and therefore have their contraction and elimination of be never discovered or known.

louci

Posted January 28, 2011 at 1:27 am | Permalink

What about it. immune response to HIV forces the virus to evolve at great speeds, so that the viral targets of the immune response change and become at least temporarily invisible.

FinallyFast

Posted February 15, 2011 at 4:14 pm | Permalink

So does this mean that while some epitopes see rapid within-host evolution on the whole the majority of the epitope population doesn’t see the same rapid evolution?

Certainly and interesting finding, but I guess it doesn’t put us any closer to figuring out how to eliminate those epitopes that are rapidly evolving.

Matt

Posted February 25, 2011 at 11:30 pm | Permalink

The virus is changing and so are we. I think that HIV will be cured or no longer a threat within ten years. Cancer is a much bigger issue because there are so many types. It has even started affecting our dogs.

Maxim Dsouza

Posted March 31, 2011 at 5:50 am | Permalink

Inspite of being such a long time since this disease started and considering the population effected, its a pity that we can neither take enough measures to prevent it, nor find a cure for it.