By Kate Kelland
LONDON (Reuters) - The world's first malaria vaccine,
made by GlaxoSmithKline, could be approved by
international regulators for use in Africa from October
after final trial data showed it offered partial protection
for up to four years.
The shot, called RTS,S and designed for children in
Africa, would be the first licensed human vaccine against
a parasitic disease and could help prevent millions of
cases of malaria, which currently kills more than 600,000
people a year.
Experts have long hoped scientists would be able to
develop an effective malaria vaccine, and researchers at
the British drugmaker GSK have been working on RTS,S
for 30 years.
Hopes that this shot would be the final answer to wiping
out malaria were dampened when trial data released in
2011 and 2012 showed it only reduced episodes of
malaria in babies aged 6-12 weeks by 27 percent, and by
around 46 percent in children aged 5-17 months.
But the final stage follow-up data published in the
Lancet journal on Friday showed vaccinated children
continued to be protected four years on, albeit at a
declining rate -- an important factor given the
prevalence of the disease -- and rates of protection
were stronger with a booster shot.
"Despite the falling efficacy over time, there is still a
clear benefit from RTS,S," said Brian Greenwood, a
professor at the London School of Hygiene & Tropical
Medicine who worked on the study.
He said an average 1,363 cases of clinical malaria were
prevented over four years for every 1,000 children
vaccinated, or 1,774 cases with a booster shot -- the
children would normally be expected to have had several
cases of infection over that period.
In babies, over three years of follow-up, an average 558
cases were prevented for every 1,000 vaccinated, and
983 cases in those who got a booster.
"Given that there were an estimated 198 million malaria
cases in 2013, this level of efficacy potentially translates
into millions of cases of malaria in children being
prevented," Greenwood said.
GSK submitted an application in July 2014 for regulatory
approval by the European Medicines Agency for RTS,S
and is expecting a decision within a few months. If it
gets a licence, the World Health Organization could
recommend it for use "as early as October this year",
Greenwood said.
Experts say RTS,S will be only one among several
weapons against malaria, alongside insecticide-treated
bednets, rapid diagnostic tests and anti-malarial drugs.
RTS,S was co-developed by GSK and the non-profit
PATH Malaria Vaccine Initiative, with funding from the
Bill & Melinda Gates Foundation.
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