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* Malaria kills more than 600,000 a year
* Vaccine could be approved for use by October
* Final findings show protection persists
By Kate Kelland
LONDON, April 24 (Reuters) - The world's first malariavaccine, made by GlaxoSmithKline, could be approved byinternational regulators for use in Africa from October afterfinal trial data showed it offered partial protection for up tofour years.
The shot, called RTS,S and designed for children in Africa,would be the first licensed human vaccine against a parasiticdisease 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 developan effective malaria vaccine, and researchers at the Britishdrugmaker GSK have been working on RTS,S for 30 years.
Hopes that this shot would be the final answer to wiping outmalaria were dampened when trial data released in 2011 and 2012showed it only reduced episodes of malaria in babies aged 6-12weeks by 27 percent, and by around 46 percent in children aged5-17 months.
But the final stage follow-up data published in the Lancetjournal on Friday showed vaccinated children continued to beprotected four years on, albeit at a declining rate -- animportant factor given the prevalence of the disease -- andrates of protection were stronger with a booster shot.
"Despite the falling efficacy over time, there is still aclear benefit from RTS,S," said Brian Greenwood, a professor atthe London School of Hygiene & Tropical Medicine who worked onthe study.
He said an average 1,363 cases of clinical malaria wereprevented over four years for every 1,000 children vaccinated,or 1,774 cases with a booster shot -- the children wouldnormally be expected to have had several cases of infection overthat period.
In babies, over three years of follow-up, an average 558cases were prevented for every 1,000 vaccinated, and 983 casesin those who got a booster.
"Given that there were an estimated 198 million malariacases in 2013, this level of efficacy potentially translatesinto millions of cases of malaria in children being prevented,"Greenwood said.
GSK submitted an application in July 2014 for regulatoryapproval by the European Medicines Agency for RTS,S and isexpecting a decision within a few months. If it gets a licence,the World Health Organization could recommend it for use "asearly as October this year", Greenwood said.
Experts say RTS,S will be only one among several weaponsagainst malaria, alongside insecticide-treated bednets, rapiddiagnostic tests and anti-malarial drugs.
RTS,S was co-developed by GSK and the non-profit PATHMalaria Vaccine Initiative, with funding from the Bill & MelindaGates Foundation. (Editing by Andrew Heavens)
