The team at the University of Oxford shows
the virus is being "watered down" as it adapts
to our immune systems.
It said it was taking longer for HIV infection to
cause Aids and that the changes in the virus
may help efforts to contain the pandemic.
Some virologists suggest the virus may
eventually become "almost harmless" as it
continues to evolve.
More than 35 million people around the world
are infected with HIV and inside their bodies a
devastating battle takes place between the
immune system and the virus.
HIV is a master of disguise. It rapidly and
effortlessly mutates to evade and adapt to the
immune system.
HIV, in red, has infected a cell in the
immune system, yellow.
However, every so often HIV infects someone
with a particularly effective immune system.
"[Then] the virus is trapped between a rock
and hard place, it can get flattened or make a
change to survive and if it has to change then
it will come with a cost," said Prof Philip
Goulder, from the University of Oxford.
Weakened
The "cost" is a reduced ability to replicate,
which in turn makes the virus less infectious
and means it takes longer to cause Aids.
This weakened virus is then spread to other
people and a slow cycle of "watering-down"
HIV begins.
The team showed this process happening in
Africa by comparing Botswana, which has had
an HIV problem for a long time, and South
Africa where HIV arrived a decade later.
Prof Goulder told the BBC News website: "It is
quite striking. You can see the ability to
replicate is 10% lower in Botswana than South
Africa and that's quite exciting.
"We are observing evolution happening in
front of us and it is surprising how quickly the
process is happening.
"The virus is slowing down in its ability to
cause disease and that will help contribute to
elimination."
Drug bonus
The findings in Proceedings of the National
Academy of Sciences also suggested anti-
retroviral drugs were forcing HIV to evolve
into milder forms.
It showed the drugs would primarily target the
nastiest versions of HIV and encourage the
milder ones to thrive.
Prof Goulder added: "Twenty years ago the
time to Aids was 10 years, but in the last 10
years in Botswana that might have increased to
12.5 years, a sort of incremental change, but
in the big picture that is a rapid change.
"One might imagine as time extends this could
stretch further and further and in the future
people being asymptomatic for decades."
The group did caution that even a watered-
down version of HIV was still dangerous and
could cause Aids.
HIV originally came from apes or monkeys, in
which it is frequently a minor infection.
Prof Jonathan Ball, a virologist at the
University of Nottingham, told the BBC: "If
the trend continues then we might see the
global picture change - a longer disease
causing much less transmission.
"In theory, if we were to let HIV run its course
then we would see a human population emerge
that was more resistant to the virus than we
collectively are today - HIV infection would
eventually become almost harmless.
"Such events have probably happened
throughout history, but we are talking very
large timescales."
Prof Andrew Freedman, a reader in infectious
diseases at Cardiff University, said this was an
"intriguing study".
He said: "By comparing the epidemic in
Botswana with that which occurred somewhat
later in South Africa, the researchers were able
to demonstrate that the effect of this evolution
is for the virus to become less virulent, or
weaker, over time.
"The widespread use of antiretroviral therapy
may also have a similar effect and together,
these effects may contribute to the ultimate
control of the HIV epidemic."
But he cautioned HIV was "an awfully long
way" from becoming harmless and "other
events will supersede that including wider
access to treatment and eventually the
development of a cure".

source :http://m.bbc.com/news/health-30254697

Ebola's influence nd interference

less deadly but still deadly.
what d advantage of sweet poison.
I respect ur research but Cure na d main thing.

Is this supposed to be good news?

braine:
Is this supposed to be good news?

na who I go ask?