of immune group in Uganda raises Aids vaccine hopes
Carroll in Entebbe and Sarah Boseley, health editor
Tuesday May 20, 2003
Scientists believe an effective Aids vaccine may be a step
closer after studying an unexpected response to the HIV virus
in individuals in Uganda who appear immune.
two dozen people near Lake Victoria have been found to remain
uninfected even though they have unprotected sex with
HIV-positive partners, a phenomenon termed "discordant
found that the immune systems of the 28 resistant individuals
behaved in surprising ways which, it is hoped, will point the
way to a vaccine within 10 years.
the resistant individuals had a lower measured immune response
than infected partners but their immune systems attacked the
virus more effectively, keeping them HIV negative. The finding
suggests that what matters is quality, not quantity, of immune
Ugandan results suggest resistant individuals are a more
widespread and significant phenomenon than first realised,
expect to cause a stir by calling on the scientific community
to focus half of vaccine research on resistant individuals, a
dramatic scaling up of what has been until now a minority
research in Entebbe takes forward the findings from studies of
a small group of commercial sex workers in Kenya. The Nairobi
women's apparent immunity triggered a line of research which
has led to the most promising vaccine now in trials, a joint
enterprise between the universities of Oxford and Nairobi.
findings come from the Uganda Virus Research Institute, which
is backed by the International Aids Vaccine Initiative (IAVI),
a not-for-profit organisation set up to channel funds into
Entebbe-based institute started phase one trials in February
of the promising DNA-MVA vaccine designed by Pro fessor Andrew
McMichael at Oxford University in collaboration with
scientists in Nairobi. Specifically designed to combat the A
strain of the HIV virus prevalent in east Africa, phase two
trials are under way in the UK and Kenya.
Ugandan discordant couple research is expected to be published
are most excited by the minority of resistant partners who
possess T-cells which kill cells infected with HIV in a
narrow, targeted attack, unlike their partners whose immune
systems launch wider, bigger - and unsuccessful - attacks.