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Ebola vaccine 100 % effective protection-trial results show


SomaNet News Archive

In what is seen as mooting "the beginning of the end" of the killer West African outbreak, an Ebola vaccine provided 100-percent protection in a field trial in hard-hit Guinea, researchers and officials said Friday, Daily Nation reported Friday citing an AFP source.

Hailing the results from the first efficacy test of the VSV-ZEBOV vaccine among people living in a high-danger zone, the World Health Organization (WHO) reportedly  said, The world is "on the verge of an effective Ebola vaccine,".

"This is an extremely promising development," added WHO chief Margaret Chan.

"An effective vaccine will be another very important tool for both current and future Ebola outbreaks."


About 28,000 people have been infected in Guinea, Sierra Leone and Liberia in the worst Ebola outbreak in history, according to the WHO, and more than 11,000 have died.

VSV-EBOV may become the first licensed vaccine against the disease for which there is also no approved treatment or cure.

The trial showed that the vaccine "offers 100 percent protection against Ebola after roughly one week," said researcher Sven Trelle from the University of Bern.

The test, backed by drug firm Merck, the WHO and the governments of Canada, Norway and Guinea, saw 4,123 high-risk people vaccinated immediately after someone close to them fell ill with the deadly haemorrhagic fever.


None of the vaccinated group caught the virus, according to study results published in The Lancet medical journal.

A second, comparison group of 3,528 people received the vaccine only three weeks after potential exposure.

Sixteen of them contracted the virus, said the study, but by day six after immunisation, the remainder of this group was also fully protected.

"Indeed, no vaccinee developed symptoms more than six days after vaccination, irrespective of whether vaccination was immediate or delayed," said the study paper.


"The initial results of the study show that the vaccine can effectively contain the further spread of the Ebola virus," added a statement from the University of Bern, which contributed to the research.

Disease experts welcomed the results.

This is big news — the most promising medical development so far in the ongoing race to shut down Ebola," Benjamin Neuman, a virologist with the University of Reading, told AFP.

Added Peter Smith of the London School of Hygiene & Tropical Medicine, the results were "very exciting and suggest that the Ebola vaccine tested may be highly effective in protecting against Ebola disease among those in the immediate vicinity of an Ebola case."

The preliminary findings on the vaccine were published in the Lancet, a British medical journal, which stated: “More data on efficacy are needed before it can be widely deployed.”
The vaccine was developed by the Public Health Agency of Canada before Merck acquiring it for testing.

Alongside this vaccine, GlaxoSmithKline and Johnson and Johnson were also developing a vaccine to tackle this infectious disease. 
The technique used in the successful trial was “ring vaccination”.


This method involves identifying a newly diagnosed person with Ebola, and then tracking down people who came in contact to the Ebola patients such as relatives and friends who were then given the trial drug.

A similar method used to eradicate smallpox.
The vaccine is not yet licensed, therefore, it will undergo intense scientific scrutiny and debate in the coming months.
Already, a Global Ebola Vaccine Implementation Team is in place under WHO’s leadership, that has been preparing the ground for its introduction—creating guidelines for the vaccine’s use, strategies for community engagement, and mechanisms to expand country capacity for the vaccine’s distribution and delivery.

The Global Alliance for Vaccines and Immunisation has approved substantial funding for the procurement and deployment of the vaccine. 
In the meantime, the Data and Safety Monitoring Board an independent body of international experts has advised that the trial should continue.

Eunice Kilonzo  of Daily Nation is credited for this report.