Human trials
underway aiming to prevent another outbreak of the virus which has swept
through West Africa
Workers
wearing protective suits in Monrovia in Liberia. Human trials are now underway
to test a vaccine that may help to prevent future outbreaks.
Hopes for an
effective Ebola vaccine have been raised after trials of an experimental jab
found that it gave monkeys long-term protection from the killer disease.
Animals that
received a first shot of the vaccine and a booster two months later were immune
to the infection for 10 months, according to US government researchers. If
further trials show that the vaccine works safely in humans, it could be used
to protect health workers and contain future outbreaks by immunising villagers
living next to affected areas.
The findings
will encourage scientists in the UK and elsewhere who have just begun human
trials of an Ebola vaccine in the hope of preventing another outbreak of the
virus which has swept through Guinea, Liberia,Sierra Leone and Nigeria,
claiming more than 2,000 lives.
The World
Health Organisation warned last week that the total death toll in African
states could reach 20,000 before it could be brought under control. The
infection is spread by contact with bodily fluids and causes fever, vomiting
and severe bleeding.
Researchers
led by Nancy Sullivan at the US National Institutes of Health (NIH) in Maryland
tested two different vaccines on macaques. The first was based on a harmless
monkey virus which had been modified to carry a protein from the Zaire strain
of Ebola, responsible for the latest outbreak. A single shot of the vaccine
protected the animals from the virus for several weeks. The same vaccine,
developed by the US NIH and GlaxoSmithKline, has just gone into human clinical
trials in the UK, Mali and the Gambia.
The US
researchers went on to test a second vaccine based on a modified cowpox virus.
Monkeys that received the vaccine as a booster two months after the first
vaccine were protected against lethal doses of Ebola for a full 10 months,
according to a report in Nature Medicine.
The Guardian
understands that UK researchers are keen to include the booster jab in future
human trials.
Jonathan
Ball, a molecular virologist at the University of Nottingham, said that a
single jab that gave even a few weeks of protection could help to contain an
Ebola outbreak.
"This
is important as it would keep the dosing regimen simple and could still provide
good protection in the sort of outbreak that we are seeing in western Africa at
the moment," he said. "For longer-term protection to prevent future
outbreaks one could envisage using the combination, the so-called prime / boost
approach."
Martin
Hibberd, professor of emerging infectious disease at the London School of
Hygiene and Tropical Medicine, said the study "gives hope for a successful
trial in humans".
On Friday,
the UN chief, Ban Ki-moon, set the goal of stopping the worst-ever outbreak of
the disease within six to nine months. The "next few weeks will be crucial,"
Ban said in New York, adding that this was an "international rescue
call".
Meanwhile,
authorities are ordering people in Sierra Leone to stay inside their homes for
three days later this month as part of an effort to stop the spread of Ebola, a
government spokesman said on Saturday. Abdulai Bayraytay said the government
was telling people to stay inside their homes on 19, 20 and 21 September. The
dates were chosen to give people enough time to stock up on food and other
provisions before the ban on movement goes into effect, he said.
Called from: http://www.theguardian.com/society/2014/sep/07/ebola-trial-vaccine-monkeys-ten-months-protect?CMP=EMCNEWEML6619I2 Guardian News and Media Limited
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