AIDS vaccine gives Africa ray of hope
-------------------------------------
by James Astill in Nairobi
Sunday February 18, 2001
The Observer
Source: http://www.guardian.co.uk/Print/0,3858,4137959,00.html
An Anglo-Kenyan team will begin trials in Nairobi this week of the
first Aids vaccine specifically designed for Africa, where 90 per
cent of Aids victims live.
The radical new vaccine is the result of a partnership between scien-
tists from the universities of Oxford and Nairobi, which nearly came
unstuck over a patent war last year. Parallel trials have already be-
gun on 18 volunteers in Britain to see if the vaccine has any toxic
effects.
The vaccine stems from the discovery that 60 prostitutes in Nairobi's
Majengo slum - around 5 per cent of the total - were immune to HIV
despite massive exposure to it. The women had between five and 10
sexual partners every day, and rarely used condoms. Up to 25 per cent
of Kenyans are estimated to be HIV positive, and in Nairobi's slums
even more.
'They didn't have the virus or the antibodies. So they must have been
getting rid of the virus so quickly that it couldn't get estab-
lished,' said Dr Job Bwayo, leader of the Kenyan team, yesterday.
Nairobi scientists discovered the women's immune systems were utilis-
ing an aggressive cell against the virus. The instant other cells be-
came infected these 'killer T-cells' destroyed them.
'We took the HIV virus and white blood cells from the prostitutes,
put them in a test-tube and - bang! - they reacted. The cells killed
the virus,' said Bwayo.
The discovery spawned similar studies around the world. A team from
Oxford's Institute of Molecular Medicine found the same phenomenon in
prostitutes in the Gambia. In 1995 the Oxford and Nairobi teams
joined forces. Backed by the New York-based International Aids Vac-
cine Initiative, their efforts have so far cost $4.5 million - a com-
parative snip.
The idea of a vaccine is to train the body's immune system to recog-
nise characteristics of an enemy virus in advance, so that it will
tell foe from friend when the attack comes. Traditionally, that has
meant injecting people with a weakened or killed version of the virus
itself, triggering antibodies.
Around 25 experimental Aids vaccines based on this principle are on
trial globally. All except one have failed to get past the prelimi-
nary test stage. The new vaccine aims to trigger a different kind of
immuno-response, producing not antibodies but cells - killer T-cells.
Results in animals have been encouraging. Around 30 per cent of mon-
keys injected with the vaccine proved immune to extremely high doses
of Simian Immunodeficiency Virus, HIV's close cousin.
Professor Andrew Mc-Michael, leader of the Oxford team, said yester-
day: 'I believe we have a really good chance of this thing working;
somewhere in the region of 70 per cent.'
McMichael confirmed that the trialists in Britain, himself included,
had suffered no side-effects. 'We didn't expect any and we're very
happy,' he said.
If the Kenyan trials go as well, the vaccine will be tried on a
large, high-risk population in 18 months. Kenya will be the perfect
testing ground because the vaccine is designed for subtype A of the
virus, the predominant strain in East Africa. All existing vaccines
target subtype B, predominating in Europe, Asia and America. 'As a
vaccine for people in the UK this would not be optimal, though we be-
lieve we could adapt it quite easily,' said McMichael.
The best case scenario would see manufacturers called in after two
years of population trials, and the vaccine widely available in an-
other two years: around six years from now. Bwayo said: 'This vaccine
may not prove to be the one. But we have hopes that, if not, one of
the modifications currently being produced in Oxford will be.'
Three months ago, such co-operation briefly seemed a distant dream.
Reports that McMichael and a colleague, Dr Thomas Hanke, had patented
the vaccine without mention of their Kenya colleagues caused a storm
in the region's media. McMichael and his colleagues flew to Nairobi
for emergency talks, and the two teams agreed to leave all patent
matters to an independent panel of experts.
Guardian Unlimited c Guardian Newspapers Limited 2001
-----------
Other recent related links on AIDS:
* Nkosi's last stand, 11-Jan2001, The Guardian:
http://www.guardian.co.uk/Print/0,3858,4115472,00.html
* South Africa fights Aids drug apartheid, 14-Jan-2001, The Observer:
http://www.guardian.co.uk/Print/0,3858,4116798,00.html
* A lot of very greedy people, 12-Feb-2001, The Guardian:
http://www.guardian.co.uk/comment/story/0,3604,436697,00.html
* The clash between science and commercial interests, 2-Feb-2001,
Australian Financial Review
http://www.healthnet.org/programs/e-drug-hma/e-drug.200102/msg00070.html
* Lamy answers EU Parliament on TRIPS and access to drugs, 20-Feb-
2001, E-Drug:
http://www.healthnet.org/programs/e-drug-hma/e-drug.200102/msg00073.html
* Glaxo's claims of patent protection on antiretrovirals in Ghana,
19-Feb-2001, E-Drug
http://www.healthnet.org/programs/e-drug-hma/e-drug.200102/msg00066.html
--
Christian Labadie
mailto:CLabadie@t-online.de
--
Send mail for the `AFRO-NETS' conference to `afro-nets@usa.healthnet.org'.
Mail administrative requests to `majordomo@usa.healthnet.org'.
For additional assistance, send mail to: `owner-afro-nets@usa.healthnet.org'.