A vaccine against the deadly Ebola virus has led to
100% protection and could transform the way Ebola is
tackled, preliminary results suggest.
There were no proven drugs or vaccines against the
virus at the start of the largest outbreak of Ebola in
history, which began in Guinea in December 2013.
The World Health Organization (WHO) said the findings,
being published in the Lancet, could be a "game-
changer".
Experts said the results were "remarkable".
This trial centred on the VSV-EBOV vaccine, which was
started by the Public Health Agency of Canada and
then developed by the pharmaceutical company Merck.
It combined a fragment of the Ebola virus with another
safer virus in order to train the immune system to beat
Ebola.
A unique clinical trial took place in Guinea. When a
patient was discovered, their friends, neighbours and
family were vaccinated to create a "protective ring" of
immunity.
Analysis
This could be the breakthrough the world has been
waiting for.
There is caution as the results are still preliminary,
with more data coming in.
But officials at the WHO believe the effectiveness of
the vaccine will end up being between 75% and 100%.
If such a vaccine was available 18 months ago then
thousands of lives could have been saved.
There are still other vaccines being trialled - notably
from GSK and Johnson&Johnson - although as the
number of cases continues to fall it is becoming
increasingly difficult to prove how effective they are.
Ebola will inevitably come again.
The hope now is that the legacy of this unprecedented
outbreak will be a vaccine that means a tragedy of this
scale can never be repeated.
One hundred patients were identified in the trial
between April and July and then close contacts were
either vaccinated immediately, or three weeks later.
In the 2,014 close contacts who were vaccinated
immediately there were no subsequent cases of Ebola.
In those vaccinated later there were 16 cases,
according to the results published in the Lancet
medical journal.
'Promising'
The WHO says it is so far 100% effective, although that
figure may change as more data is collected.
Close contacts of Ebola patients in Guinea will now be
vaccinated immediately. And since the vaccine has
been shown to be safe, that process will also be
extended to include children.
Médecins sans Frontières (MSF) is involved with this
research, and is part of a parallel trial for frontline
healthcare workers.
Medical director Bertrand Draguez said the Lancet
results should spur instant action.
"With such high efficacy, all affected countries should
immediately start and multiply ring vaccinations to
break chains of transmission and vaccinate all frontline
workers to protect them."
Marie-Paule Kieny, an assistant director general at the
WHO told BBC News: "It is certainly promising. We
have seen that where rings have been vaccinated, the
transmission has stopped.
"Prior to vaccination there were cases, cases, cases.
The vaccine arrives and 10 days later the cases are
flat.
"It could be a game-changer because previously there
was nothing, despite the disease being identified 40
years ago.
"When there is a new outbreak this vaccine will be put
to use to stop the outbreak as soon as possible to not
have the terrible disaster we have now."
More than 11,000 people have died from Ebola and
nearly 28,000 have been infected.
The sheer scale of the 2014-15 outbreak led to an
unprecedented push on vaccines - and a decade's work
has been condensed into around 10 months.
The number of cases has fallen - and in the week up to
July 26th 2015 there were just four cases in Guinea
and three in Sierra Leone.
Prof John Edmunds, from the London School of
Hygiene & Tropical Medicine, helped design the trial:
"The development has been at an absolutely
unprecedented speed.
"This is very good news, these are very significant
results, the epidemic is not over and this shows we
have another potential weapon.
"The trial is still continuing, these are interim results
which need confirming, but there's now light at the end of the tunnel.
Source:
BBC News
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