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* GSK shot likely to cost $5/dose, won't stamp out malaria
* Pilot tests in children expected to take 3-5 years
* Experts don't recommend use of vaccine in young babies (Adds detail on cost; comment from GSK, MSF, outside expert)
By Tom Miles and Ben Hirschler
GENEVA/LONDON, Oct 23 (Reuters) - The world's first malariavaccine is promising but should be used on a pilot basis beforeany wide-scale use, given its limited efficacy, World HealthOrganization (WHO) experts said on Friday.
The decision is likely to delay a possible broad roll-out ofthe shot for between three and five years.
GlaxoSmithKline's Mosquirix could, in theory, helpstop millions of cases of malaria in young children in Africa atrisk of the deadly mosquito-borne disease.
However, it is less effective than vaccines against manyother diseases and there is uncertainty as to whether countriescan effectively administer the four doses needed.
Jon Abramson, chairman of the WHO Strategic Advisory Groupof Experts, or SAGE, said experts recommended there should bethree to five demonstration projects in children aged five to 17months before considering wider use.
These projects could involve up to 1 million children andwould likely take three to five years to run, he added. SAGE didnot recommend the use of Mosquirix, also known as RTS,S, inyoung babies.
Committee experts said it was vital to give all four dosesof the vaccine to ensure optimal efficacy, even though gettingchildren back for multiple repeat shots could be challenging.
"If we can't get four doses of this vaccine into thechildren, we're not going to be using it," Abramson toldreporters.
"What we are recommending is that before we have widespreaduse of this vaccine - and we wouldn't necessarily use it in avery low incidence area, but in all medium and high areas - thatwe know that we can get that fourth dose in."
Hopes that GSK's vaccine could wipe out malaria weredampened when trial data in 2011 and 2012 showed it reducedmalaria episodes in babies aged six to 12 weeks by only 27percent, and by about 46 percent in children aged five to 17months. Part of that could be down to genetics.
'A TON OF MONEY'
GSK said it was ready to work with the WHO to support thepilot implementation of the vaccine. "We hope this will providethe additional information needed about how to best deliver thevaccine in a real-world setting," a spokeswoman said.
Abramson said the vaccine was likely to cost around $5 adose, or $20 for a four-dose course, which is four times thecost of an insecticide-treated bed net. It could be funded bythe GAVI international vaccine alliance, though no decision onthis has yet been made.
"If this vaccine is not effective and we use it widely wewill have spent a ton of money which could have been betterplaced," Abramson said.
Medical charity Medecins Sans Frontieres said SAGE was rightto be wary about using a costly intervention with a patchyrecord.
Adrian Hill, a vaccine expert at Oxford University's JennerInstitute, told Reuters: "This really underscores the need forwork on developing other promising malaria vaccine candidates tobe accelerated."
Alternative malaria vaccines are still at least five to 10years away from being licensed.
This year alone, there have been an estimated 214 millionnew cases of malaria, with around 438,000 deaths.
GSK has said it will not make any profit on Mosquirix, sincea planned mark-up of just 5 percent on the cost of productionwill be reinvested in research on tropical diseases.
The shot also contains an adjuvant, or booster, made by U.S.biotech company Agenus. (Additional reporting by Kate Kelland; Editing by David Holmesand Mark Potter)
