Sunday, March 1, 2009

HIV Evolution

By Angrette

It is estimated that HIV had already killed 25 million people and an estimated 33 million are currently infected. However the virus does not kill people at the same rate. The rate of progress is tied to to the rates by which genes that control production of key immune system molecules called Human Leucocyte Antigents or HLA's are produced. Humans differ in the amount HLA's genes they have, small differences have a big impact on how quickly AIDS developed. Researchers found mutations in HIV that enables the virus to effectively neutralise the effect of a particular HLA, when that HLA have high prevalence in a population. With time the HIV virus has developed escape mutations in its genetic make up. This shows that HIV is very adept at adapting to the immune responses of human populations that are most effective at containing the virus. The first reaction would be to think that the virus is winning the battle. Not necessarily, other researchers had said that it could actually be that as the virus changes, different immune responses come to play and are actually more effective. The implication is that if a vaccine is found it would need to be changed on a frequent basis to catch up with the evolving virus.

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