* Supply challenge after green light to use unproven drugs
* Race to scale up production, testing of Ebola treatments
* Two vaccines set to enter clinical trials in coming weeks
By Ben Hirschler
LONDON, Aug 12 World Health Organization experts
fighting the world's worst outbreak of Ebola hope for improved
supplies of experimental treatments and progress with a vaccine
by the end of the year.
That may come too late to put an end to the current
epidemic, which is more likely to be stopped by standard
infection control measures, but it offers hope for the next
After ruling on Tuesday that it is ethical to offer unproven
Ebola drugs to people infected or at risk in West Africa, the
challenge is to secure enough doses to make a difference in an
outbreak that has already claimed more than 1,000 lives.
An experimental drug called ZMapp from U.S. firm Mapp
Biopharmaceutical appears to have had "a dramatic and very rapid
effect" in the case of two U.S. doctors, WHO assistant
director-general Marie-Paule Kieny told reporters.
However, the scant supplies of this drug are now effectively
exhausted, after Liberia secured doses for two of its doctors.
Spain's Health Ministry said a 75-year-old Spanish priest, the
only other person known to have been given ZMapp, had died.
One of the deadliest diseases known to man, Ebola kills the
vast majority of those infected. Its symptoms include internal
and external bleeding, diarrhoea and vomiting.
Other drugs are also at an early stage of development,
including a treatment from Tekmira Pharmaceuticals that
was cleared last week by U.S. regulators for testing in infected
None of these, however, is available in the quantities
needed to make a dent in the West African epidemic - even if
they work as well as hoped.
Still, the WHO is optimistic supplies can be ramped up by
around the turn of the year, although the number of doses
available will likely still remain insufficient to meet demand.
The United Nations agency also believes a vaccine can be
fast-tracked for use in those most at risk, such as healthcare
workers caring for patients, laboratory technicians and people
burying the dead.
Kieny said two vaccine candidates were set to enter clinical
trials in the coming weeks and there could be enough early-stage
data to consider their emergency use by the end of 2014.
"We could have enough information, very preliminary, but
maybe enough information on their safety in humans by the end of
the year," she said. "There is a way to fast-track clinical
The two vaccines due to enter the first phase of human
testing have been developed by GlaxoSmithKline and
Normally, it takes many years to test a new drug or vaccine
and determine it is safe for use, so the bar will be lowered
significantly in the case of Ebola. That worries some experts.
"So far these therapies have been tested only in a handful
of monkeys," said Kevin Donovan, director of the Center for
Clinical Bioethics and a professor of paediatrics at Georgetown
University, speaking on a panel convened on Tuesday by the
O'Neill Institute for National and Global Health Law.
"We don't know what harm they will do over the long term or
even the short term. We owe it to the Ebola victims, current and
potential, to get this right."
The decision to support the use of unproven treatments
reflects the deadly nature of the disease and the need to close
the research gap left by the pharmaceutical industry's failure
to tackle a neglected tropical disease found in poor countries.
"The fact that there is currently no registered drug for
Ebola is a market failure," Kieny said. "If it hadn't been for
the investment of a few governments into the development of
these drugs and vaccines, we would be nowhere."
There has been an outbreak of Ebola every few years since
the virus was first discovered nearly 40 years ago in the
forests of central Africa.
But it is only in the past 10 years or so that researchers -
prompted in part by the perceived bioterror threat posed by
Ebola - have started to look seriously at the disease,
generating the current range of potential drugs and vaccines.
(Additional reporting by Kate Kelland, Stephanie Nebehay and
Toni Clarke; editing by David Clarke)