This is good news and could even be good enough if it is combined with all the other therapies and protocols as well. Good enough means making the disease very rare and largely treatable. Removing even a third of the victim pool is a great start.
This is a real advance that can save millions of lives. Even better health care is also advancing everywhere in the tropics so it may well be the right time also.
We still want to erradicate the problem but success there has also been spotty or at best partial. True eradication must await a far deeper level of social and economic development as well as the well known Italian case study showed so well. .
Malaria vaccine candidate shown to prevent thousands of cases
http://www.gizmag.com/malaria-vaccine-candidate-trial/37205/
A new study suggests that RTS,S/AS01, the prime candidate for a
malaria vaccine and the first one to reach large-scale clinical testing,
is partially effective especially among young African children for a
period of up to four years after vaccination. The vaccine could
potentially prevent millions of cases of clinical malaria, particularly
in areas of high transmission like sub-Saharian Africa, and in the age
group in which malaria is known to be the most lethal.
The World Health Organization (WHO) estimates
that 1.2 billion people around the world are currently at high risk of
contracting malaria. In 2013, as many as 283 million cases of this
debilitating disease are thought to have caused nearly 600,000 deaths.
It is also estimated that around 90 percent of those deaths took place
in Africa, and about three in four casualties were children below the
age of five.
The search for a malaria vaccine has spanned many decades and has produced several promising candidates, although the vast majority of candidate vaccines have only been tested on a handful of patients at a time in what’s known as a "phase I" testing.
Vaccine candidate RTS,S/AS01 is the first to have reached phase III
of clinical testing. This phase consists of a series of randomized,
controlled tests conducted by multiple clinics on hundreds or thousands
of patients, with the goal of assessing the effectiveness of the drug
over several years. After nearly four years of testing, this phase has
finally reached its conclusion and researchers have announced its
results, which look promising in many respects.
The RTS,S/AS01 vaccine was developed for use in sub-Saharan Africa,
the area where malaria is most widespread and kills around 1,300
children every day. The trial enrolled 15,459 young infants (aged 6-12
weeks at first vaccination) and children (5-17 months at first
vaccination) across seven countries.
The preliminary results published last year had shown a vaccine
efficacy of about 46 percent in children and around 27 percent among
young infants after a period of 18 months. In this latest study,
researchers followed up on their patients for a further 20 to 30 months
to evaluate the impact of a fourth booster dose.
The results suggest that the effects of a booster dose are positive,
even though the overall efficacy of the vaccine seem to wane with time.
One year after their first shot, children saw malaria incidence reduced
by 50 percent, versus just 36 percent four years later for the children
who received three shots and a booster dose. However, in children, the
booster dose recorded a 32 percent efficacy against severe malaria,
while missing the booster dose reduced the efficacy against severe
malaria to a negligible effect.
Unfortunately, the vaccine was shown to be less effective for
infants. In those who received three doses of vaccine plus a booster,
the four shots reduced the risk of clinical episodes of malaria by 26
percent over three years, but there was no significant protection
against severe malaria.
"Despite the falling efficacy over time, there is still a clear
benefit from RTS,S/AS01," says study author Prof. Brian Greenwood. "An
average 1,363 cases of clinical malaria were prevented over four years
of follow-up for every 1,000 children vaccinated, and 1,774 cases in
those who also received a booster shot. Over three years of follow-up,
an average 558 cases were averted for every 1,000 infants vaccinated,
and 983 cases in those also given a booster dose."
According to Greenwood, this level of efficacy could potentially
translate into millions of cases of malaria in children being prevented.
WHO data suggests that the incidence of malaria has decreased by 30
percent globally since the turn of the century, and that the mortality
rate has halved during the same period. This has been largely because of
a host of widespread preventative measures including mosquito nets,
rapid diagnostic testing and improved access to treatment. So, although
the results of this large-scale test are exciting, it will be important
not to steer funding away from these measures as a malaria vaccine is
rolled out.
The European Medicines Agency (EMA) will now assess the safety and
efficacy of the vaccine based on the latest data. According to
Greenwood, should the assessment be positive, the World Health
Organization could recommend the use of the vaccine as early as October
this year and could become the first ever licensed human vaccine against
a parasitic disease.
The results were published in the journal The Lancet.
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