VSV-ZEBOV was originally developed by Canada’s public health agency before being licensed to NewLink Genetics, which then signed a deal handing Merck the responsibility to research, develop, manufacture and distribute it.
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“We’re fully committed to working with regulatory authorities to define what the requisite data is and provide it as quickly as we can do so”, said Dr. Mark Feinberg, chief public health and scientific officer at Merck Vaccines.
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.
After that point, none of the people in the group that had been assigned to get the vaccine right away developed Ebola, versus 16 people in the group eligible to get the vaccine after 21 days.
Dr. Margaret Chan, director general of the World Health Organization, said if the preliminary results are confirmed, the vaccine “is going to be a game-changer”.
Officials from the World Health Organization said more research would be needed to confirm the early findings from the Guinea-based study. “It will change the management of the current Ebola outbreak and future outbreaks”.
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. It works by creating a buffer of protection to prevent the spread of the disease, by vaccinating and monitoring the contacts, and contacts of contacts – the “ring” – of each newly diagnosed Ebola case. A paper published today in the British medical journal Lancet reports that the vaccine, which has been tested in Guinea since March 2015, has shown extraordinary results so far, with 4,123 people voluntarily vaccinated and all safe from the disease.
Because Merck’s VSV-ZEBOV is a live, or replicating, vaccine, there were initial worries about its safety.
The latest medical trial was tested on thousands of people in Guinea and provided 100 per cent success rate in stopping the disease developing in all those it was immediately given to.
The Gavi Alliance, which buys vaccines in bulk for poor countries who struggle to afford them, immediately said it would back an Ebola shot once it is approved.
“The study is really great news”, Adalja said.
The technique used in the successful trial was “ring vaccination”. One reason was a sharp drop in the number of new cases in Africa over the past few months.
After seeing the devastation of the disease with no clear treatment or vaccine, he said the vaccine is “certainly helpful”, but remains concerned people will assume it can end the outbreak alone. The vaccine, in other words, worked with 100% efficiency as far as those enrolled in the trial were concerned.
Jeremy Farrar, a leading infectious disease specialist and director of the Wellcome Trust, which helped fund the trial, described the results as “remarkable“. For example, there were more than 1,000 people in the study who were not vaccinated at all – some did not consent to vaccination, and others did not show up for vaccination.
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“By this time we were thinking that this vaccine would have been up and running, and that people would have been benefiting from it already.” said Yumkella.
