Ebola virus under the microscope
With hundreds of cases of Ebola in Africa, health
experts are looking at whether the use of
experimental drugs is justified.

What is the current treatment for Ebola?
There is no licensed treatment or vaccine for the
Ebola virus. Hospital treatment is based on giving
patients intravenous fluids to stop dehydration and
antibiotics to fight infections. Strict medical
infection control and rapid burial are regarded as
the best means of prevention.
What about experimental treatments?
Several experimental treatments for Ebola are
being developed, which have shown promising
results in monkeys when given up to five days
after infection. However, they have not been tested
in more than a handful of people and none have
been licensed.

Two US aid workers have been given an
experimental treatment, known as Zmapp, with
"apparently encouraging" signs in one of them,
said Prof Tom Solomon, director of the NIHR
Health Protection Research Unit in Emerging
and Zoonotic infections. The treatment is a
mixture of three monoclonal antibodies
against the Ebola virus, produced in
bioengineered tobacco plants.

Another experimental drug, developed by
Tekmira Pharmaceuticals in Canada, has been
tested on monkeys and in a handful of healthy
human volunteers. The drug, TKM-Ebola, is
designed to target the strands of genetic
material of the virus (RNA). A small early
safety trial on a small number of human
volunteers was put on hold last month when
regulators requested further safety data. The
Fcompany is hopeful that it may get the go-
ahead to continue the trial and is willing to
make the drug available.
The US-based pharmaceutical company,
Sarepta Therapeutics , has developed a similar
RNA treatment. It has been tested in healthy
human volunteers in early safety trials, but has
never been tried in a human patient.
What is serum?
Serum - the part of the blood that contains
antibodies - has been used in past Ebola
outbreaks. Survivors have high levels of antibodies
against the virus in their blood. In one outbreak in
1995 in the Democratic Republic of Congo, seven
out of eight patients survived after being treated
with serum from survivors, according to Prof
Solomon. Reports suggest that the US aid workers
who developed Ebola may have been given serum
before being flown home from Africa.
What other approaches are being tried?
Scientists have been working on a number of
prototype vaccines against Ebola. Most are in very
early stages of research in animal models and no
vaccine has been licensed.
The natural host for the virus is the fruit bat
The Food and Drug Administration in the US says
it is fast-tracking a vaccine that has shown
encouraging signs in monkeys for phase 1 trials in
September.
This type of trial is the earliest study in humans
and aims to make sure that drugs are safe and
show some chance of working.
What are the chances of success?
Experts say that pharmaceutical companies are
unlikely to invest the huge resources needed to
develop new drugs when these would likely be
used only occasionally in relatively small numbers
of people. They say investment is needed from
international agencies to have any realistic chance
of success in the future.
The use of experimental treatments and vaccines
has also raised ethical dilemmas. The World
Health Organization (WHO) is convening a panel of
medical ethicists to explore the use of
experimental treatments.
It says the recent treatment of two health workers
with experimental medicine has raised questions
about whether medicine that has never been
tested and shown to be safe in people should be
used in the outbreak and if it is used, who should
receive it.
"We are in an unusual situation in this outbreak.
We have a disease with a high fatality rate without
any proven treatment or vaccine," says Dr Marie-
Paule Kieny, Assistant Director-General at the
WHO.

pls is tomorrow friday or sunday?