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* Ebola virus one of most deadly known in humans
* 62 dead in suspected Ebola outbreak in Guinea - WHO
* Drug investment scant due to likely lack of return
* U.S. government funds research due to bioweapon fears
By Kate Kelland, Health and Science Correspondent
LONDON, March 27 (Reuters) - Almost 40 years after the Ebolavirus was identified in humans by scientists in a microbiologylaboratory in Belgium, pharmaceutical researchers have yet todevelop an effective drug or vaccine to fight it.
Part of the problem is that the deadly virus is rare and itsvictims are often poor people living in rural areas of Africawithout well-functioning health systems. But there is alsolittle incentive for major pharmaceutical companies to invest inmedical solutions when there is little chance of a return.
The number of doses sold is likely to be small and manyhealth officials believe the virus and its death toll could bebetter controlled with good basic hygiene and the eradication ofdangerous bushmeat consumption.
Yet there is a drug development pipeline, of sorts, outthere - mainly funded by the U.S. government which fears suchdeadly viruses might one day be developed into bioweapons.
"We can do basic research quite cheaply, but when you movefrom that to trying to develop drugs and vaccines, you get intothe need for clinical trials and they are very costly - which iswhere you would normally start to engage with Big Pharma," saidJonathan Ball, a professor of molecular virology at Britain'sUniversity of Nottingham. "And clearly they are not going toinvest unless there is likely to be some sort of decent return."
Discovered in 1976 after an outbreak in the DemocraticRepublic of Congo, then Zaire, Ebola causes a severehaemorrhagic fever where victims suffer vomiting, diarrhoea andboth internal and external bleeding.
In an outbreak in Guinea in West Africa, about 86 suspectedcases have been reported, with 62 deaths, according to the WorldHealth Organisation. Investigations are going on into reportedcases in Liberia and Sierra Leone along the border with Guinea.
BIOWEAPON FEARS
"Ebola virus is one of the deadliest killers known," saidBen Neuman, a virologist at Britain's University of Reading."(It) is one of the things that keeps public health officials upat night. If this virus spread between people more easily, itwould probably be more deadly than the black plague.Fortunately, up to this point, it has not."
So while for drugmakers there is little commercial future inEbola, some research groups in the United States are working inconjunction with the U.S. government to find treatments.
In March, the University of Texas and three otherorganisations got $26 million in funding from the U.S. NationalInstitutes of Health to find a cure for Ebola and another deadlyvirus Marburg in case they are ever used for bio-terrorism inthe United States.
Tekmira Pharmaceuticals, which teamed up with theU.S. Department of Defense on an injectable drug treatment forEbola, started an initial Phase I trial in healthy volunteers inJanuary.
Several small biotech companies and U.S. universitydepartments are also developing potential vaccines, but thiswork has yet to advance from animal studies into clinical trialsin humans - so any use in people now would be very risky.
U.S.-based Inovio and privately held Vaxart areamong those with experimental vaccines in animal testing, whileGlaxoSmithKline last year acquired Swiss vaccine firmOkairos with an early-stage Ebola product.
"There are a few experimental vaccines, but the question iswhether anybody would take on the costs of manufacture based onthe likely number of doses they would eventually sell," said IanJones, a professor of virology at Reading University.
"The numbers of people infected are low, and at the end ofthe day somebody has to fund the production of a drug orvaccine. As things stand that is unlikely."
DRUG TRIALS
The immense difficulty and high cost of conducting humanclinical trials for a potential drug or vaccine are prohibitive,experts point out, since Ebola cases are generally far flung,rare and unpredictable.
"For a start there are simply not enough patients and youwouldn't know when the next outbreak was going to happen," saidJones. "Even then you couldn't guarantee there would be enoughpeople to run a trial. Which means you would have to go from thebest evidence in animal models."
Some scientists say the current outbreak in Guinea could bean opportunity to do just that - offering a chance to push thefield forward and test potential vaccines or drugs.
Thomas Geisbert at the University of Texas Medical Branch isworking on a vaccine known as vesicular stomatitis virus-basedEbola vaccine, or VSV, which he said had shown 100 percentefficacy in tests on animals.
The shot, which has not gone through clinical trials inhumans, could, he said, be issued on "compassionate grounds" topeople in Guinea at risk in the current Ebola outbreak.
"You have to reach a balance between advancing science,medical ethics and saving lives," he told Reuters. "It's noteasy, but how many people faced with the prospect of nearcertain death would opt to take their chances with the virus?" (Additional reporting by Ben Hirschler in London and MishaHussain with the Thomson Reuters Foundation in Dakar; Editing byJanet Lawrence)
