BG> it'll be interesting if they manage to find
BG> out why those women are immune to HIV too.

RS> Its a different strain which produces that. Strain
RS> of HIV. HIV is rather easy to work the DNA out with,
RS> thats what determines the strain, the DNA sequence.

BG> What's the actual scenario though?  Haven't they just
BG> basically contracted a certain viral strain which doesn't
BG> sero-convert, which means that they'll not develop
BG> full-blown AIDS from just THAT particular virus?

Nope, the theory is that just like an attenuated live virus makes you
immune to the full virus, that strain makes you immune to HIV coz its
close enough to the strains that kill, but doesnt itself do that. In
other words its close enough to fool the immune system but is safe.

BG> I presume also that HIV antibodies are still present, regardless?

Yes, which is why you show positive to an HIV
test if that is used as an HIV vaccine.

Thats just as true with vaccination with other infectious diseases,
you know the vaccination 'took' because of the antibodies produced.

BG> I'd have expected scores of different strains by now though.

RS> There are. Its just that its extremely rare that
RS> you have a strain which does not ever sero convert.

BG> OK, so does that mean they can never progress beyond a certain stage?

Thats one question mark about it. All we actually know is that it doesnt
sero convert like the other ones do in the period we have observed it for.
Doesnt ever sero convert in that period. BUT we dont know with absolute
certainty that it doesnt sero convert after say 50 years instead. Thats
theoretically unlikely, but its possible. Some viruses have extremely long
inactive phases. Its just unlikely its managed to accidentally mutate into
such a different type of behaviour.

BG> Why is it that HIV appears not to mutate as
BG> frequently or as quickly as most other viruses?

RS> In fact it mutates a lot faster than most.

BG> Mainly lethal though,

Yes, almost all lethal.

BG> or do they mutate into relatively harmless strains?

Hardly ever. The number of harmless ones is
a very very small fraction of the lethal ones.

RS> The only common ones that mutate faster are flu and colds etc.

BG> True, makes me wonder why I really bother with my annual Fluvax...

Well, it does work in that year, its just a damned nuisance
to have to have to do it every year instead of once for life.
@EOT:

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