Changing drug resistance of the AIDS virus

From BBC news: Aids virus ‘could be weakening’

I’m not familiar with the HIV field of research, nor have I read this particular paper, but I strongly suspect that this refers to a small cohort, probably in Belgium (facts need to be checked when I have access to the paper). The way the AIDS virus is spread probably means that in different populations, the strains are vastly different. While it sounds like the recent viral samples they’ve extracted from their (untreated?) patients are more sensitive to drug treatment in cultured cells than virus samples collected 15-20 years ago, there’s no guarantee that the viruses in other populations are undergoing the same “attenutation” (or weakening). While I’m happy for those who have the weaker, more treatable, virus, I’ve seen reports that the exact opposite is happening in other studies, where an increase in drug-resistance is seen.

Let’s just hope those who pretend that AIDS is an epidemic that will just go away of its own accord fail to latch on to this particular finding.

Update: The BBC page has an audio link to an interview with Dr. Eric Artz. In summary, he refers to the way viruses lose pathogenicity (i.e. are less lethal) over time as the mechanism for survival of the virus. And suggests this may be happening with HIV-1, and could mean the virus will cause fewer fatalities in several decade.

My understanding: With viruses that are dependent on their hosts to survive and replicate, the adage “survival of the fittest” is not always true. A super-strong virus that ends up killing its host soon runs out of warm bodies to infect (in an idealised world, where local populations stay local and don’t move about too much…). Case in point: the ebola virus. My guess is that these viruses die out with their local population of hosts, and the weaker mutants, which don’t cause immediate death, will survive another day to infect another host.

Update 2: Having skimmed through the paper, it looks like they looked at two different scenarios: one where they allowed pairs viruses to infect cells in culture and compared the historical and recent viruses’ abilities to replicate in competition with each other (indicator of their pathogenicity, don’t know how it works), and another where they treated uninfected cells in culture with entry inhibitors, then infected them (measure of drug-resistance).

Their findings? Recent viruses are less “fit”, and lose out in direct competition with the historical ones. And recent viruses are a little less able to infect cells treated with entry inhibitors.

[Disclaimer: This is super-simplified and over-generalised. I really don’t know anything about viruses, let alone the ins-and-outs of HIV-1. Other factors to take into account include period, method and range of infection, immune response, disease progress and bloodymindedness of humans and drug companies…]

And as is pretty obvious, I’m work-avoiding… Pseudo-science on a blog being easier to write my own stuff.

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