WHO announces ultra-effective vaccine against Ebola virus

Health 23 December, 2016

This vaccine was injected to 5,800 people in Guinea who had contact with a patient with the virus. None developed the disease.

His name is rVSV-ZEBOV (for recombinant vesicular stomatitis virus Zaire ebolavirus , or French “stomatitis virus recombinant vesicular-Ebola”) and it could stop a future outbreak of Ebola. The World Health Organization (WHO) presented Thursday, December 22, an effective vaccine against the virus that has claimed more than 11,300 deaths in Africa West between 2013 and 2015. This is an advanced In the face of a disease that has been raging since at least 1976.

The vaccine developed by the Canadian government was injected into Guinea to 5 800 people who had contact with a patient with the virus. No cases of Ebola were observed in persons vaccinated within 10 days. “This strongly suggests that the vaccine could have an efficacy up to 100%” , welcomes Marie-Paule Kieny, Assistant Director-General for WHO, adding,

“If there was a case of Ebola and a new epidemic, we are now ready to be responding . ”
His team of researchers calculated that in the event of a full epidemic, there was a 90% chance that the vaccine would be more than 80% effective. ” The protection occurs very early after vaccination, but we do not know if it will last another six months,” warned M me Kieny.

Two adverse effects “serious” were related to vaccination (a febrile reaction and allergic reaction) and a third qualified as possible (ILI), but with a recovery in the three cases, no long-term effect. Initially excluded from the trial, children over 6 years of age subsequently benefited. But it remains to determine its safety for pregnant women and the little ones.

The vaccine, produced by Merck, is named rVSV-Zebov.

“Ring vaccination”

The test was done using a method called “ring vaccination” . That is, circles or groups of people in contact with a patient, first relatives, then subjects who have been in contact with them, and so on. This is the same method that was used to eradicate smallpox.

After the end of the test, there have been few cases in Guinea and in Sierra Leone , and the team used the same strategy: vaccination of contacts of contacts, with the permission of the FDA (the US Agency for food and drug Administration) to use the vaccine outside of a clinical trial, told M me Kieny.

Read also: The anxiety of the doctor before his first Ebola patient

300,000 emergency doses

The US Merck laboratory acquired the marketing rights of the rVSV-Zebov. The standard approval process with the US and European drug agencies takes about ten years. However, of three hundred thousand to one million emergency doses could be delivered before the commercialization of the vaccine.

According to results released Friday, December 23 in the medical journal The Lancet , rVSV-ZEBOV is effective against the strain called “Zaire”, but another vaccine must be developed to fight against the strain Sudan . Other vaccines are also needed, especially for caregivers, making sure they offer long-term protection. Several are in development .