Home' Trinidad and Tobago Guardian : April 25th 2015 Contents Final clinical trials of a malaria vaccine---the
first to reach this stage---suggest it could help pro-
tect millions of children against malaria.
But tests on 16,000 children from seven African
countries found that booster doses were of limited
use and vaccines in young babies were not effec-
After children aged 5-17 months were given three
doses of the vaccine, the immunisation was only
46 per cent effective.
But experts say getting the vaccine this far is a
scientific milestone. Data from the trial published
in The Lancet showed that the success rate fell to
even lower levels in younger infants.
Scientists have been working on the vaccine for
more than 20 years, but observers believe there is
still a long way to go.
RTS,S/AS01 is the first malaria vaccine to reach
advanced trials and show any sign of working in
young children. There is currently no licensed vac-
cine against malaria anywhere in the world.
With around 1,300 children dying in sub-Saharan
Africa from malaria every day, scientists say they
are delighted to have got to this stage in developing
a vaccine against a very clever parasite.
Prof Brian Greenwood, study author and professor
of clinical tropical medicine at the London School
of Hygiene and Tropical Medicine, said he was "a
little disappointed" by the results of the clinical
"I hoped the vaccine would be more effective,
but we were never going to end up with the success
seen in measles vaccines with 97 per cent effica-
cy."That is because the malaria parasite has a com-
plicated life cycle and it has learnt how to evade
the immune system over hundreds of years.
The vaccinations took place at 11 sites across
Burkina Faso, Gabon, Ghana, Kenya, Malawi,
Mozambique and Tanzania. The trials found the
vaccine s ability to protect children gradually waned
Scientists tried to bolster this with a booster,
but protection never reached the level provided by
initial doses. The clinical trials also found that
meningitis occurred more frequently in children
given the vaccine.
Vaccine can reduce attacks by 30%
However, Prof Greenwood said the data was very
robust and the vaccine could still reduce attacks
of malaria by around 30 per cent.
The European Medicines Agency will now review
the data and, if it is satisfied, the vaccine could be
licensed. And the World Health Organization could
then recommend its use in October this year.
Prof Adrian Hill, at the University of Oxford,
said although the study was "a milestone", he had
"Because the vaccine s efficacy is so short-lived,
as expected a booster dose is shown to be of some
value---but it was not as effective at the initial
doses. More worrying is the new evidence of a
rebound in malaria susceptibility: after 20 months,
vaccinated children who were not boosted showed
an increased risk of severe malaria over the next
27 months compared to non-vaccinated controls."
Overall, he said the vaccine s potential public
health benefits were not yet clear.
"It should be possible to make the vaccine more
effective in some settings, but that will probably
increase delivery costs substantially."
Prof Mike Turner, head of infection at the Well-
come Trust, said it had taken two decades to get
to this point.
"While the levels of protection the vaccine offers
against clinical malaria may seem relatively low,
they are better than any other potential vaccine
we currently have. The findings are not only impor-
tant in their own right but also in signposting a
road to developing better vaccines in the future."
James Whiting, from the charity Malaria No
body & soul
Guardian www.guardian.co.tt Saturday, April 25, 2015
More UK, said it was a huge achievement to get
the vaccine this far.
"There are still a number of considerations and
approval processes to be undertaken, but it has the
potential to be an important additional tool to fight
malaria and save lives from a disease that kills a
child every minute."
Other experts warned that funding for a vaccine
should not be redirected away from insect nets and
other malaria control measures. (BBC)
Scientists say that
the malaria parasite
mosquitoes is clever
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Child malaria vaccine: Final trials bring hope
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