drug trial success boosts hope of defeating Malaria
A PAIR of experimental vaccines against malaria could prevent tens of thousands of cases of the disease a year, a review of recent studies has found.
An analysis of six candidate vaccines being tested in Africa, conducted
for the renowned Cochrane Library, has confirmed that two of these show promise, raising hopes of a breakthrough against the world’s second most deadly infectious disease.
The most encouraging results are for a vaccine known as RTS,S, after studies in Mozambique and The Gambia suggested that it could provide children and adults alike with significant protection against malaria.
The Cochrane review backs most of the conclusions of two trials of the vaccine, developed by GlaxoSmithKline with the Walter Reed Army Research
Institute in the US, which have already been published in The Lancet.
It prevented 58 per cent of the most severe cases of malaria among
children in Mozambique, and reduced the total number of cases in the same
group by 26 per cent. It was effective for up to 18 months after
immunisation.
A follow-up study of adult men in The Gambia indicated that immunising them and then giving a booster jab a year later reduced clinical cases of malaria by 63 per cent.
Patricia Graves, of EpiVac Consulting in Atlanta, Georgia, who led the Cochrane investigation, described the trials as extremely promising.
There is currently no effective vaccine against malaria, which kills more people than any infection apart from HIV/Aids.
The parasite causes between 300 million and 500 million new cases annually, mostly in children in sub-Saharan Africa, and between 1 million
and 2.7 million deaths.
The trials’ endorsement by the Cochrane Library is significant because the independent non-profit organisation is dedicated to examining the quality
of the design and results of medical research. It aims to provide an
overall picture of the evidence for and against particular drugs and
vaccines, to allow doctors to make informed decisions about their use.
Its investigation was also cautiously positive about trials of a different
malaria vaccine, known as MSP/RESA or Combination B, which appears to
reduce the severity of some malaria infections. It is most effective
against one strain of the Plasmodium falciparum parasite that causes the
disease, found in Papua New Guinea. “In light of this proof of principle,
the vaccine should undergo further development to improve its
effectiveness,” Dr Graves said.
The two vaccines work on different principles, and may even be complementary.
Neither of them was found to have common severe side- effects; the worst
of them was generally confined to arm pain at the site of injection.
The Cochrane review of early-stage malaria vaccines included 11 studies
and more than 3,000 participants.
The blood stage review included five studies and 217 people.
Full story at: http://www.timesonline.co.uk/article/0,,3-2408669,00.html
18 October 2006
Source: TIMESONLINE.COM |
