The vaccine was administered to 20 volunteers, compelled their immune systems to produce Ebola antibodies

Nov 27, 2014 12:14 GMT  ·  By

Just yesterday, researchers with the US National Institute of Allergy and Infectious Diseases (NIAID) announced that, having administered an experimental Ebola vaccine to a group of volunteers, they found it to be safe and effective.

More precisely, the scientists behind the investigation said that, according to evidence at hand, the vaccine successfully triggered an immune system response in all the adults who agreed to take part in this series of experiments.

The ins and outs of this experimental Ebola vaccine

In a statement, NIAID scientists explain that the experimental Ebola vaccine they got to test on humans is the result of a collaboration with Okairos, a biotechnology company acquired by British healthcare giant GlaxoSmithKline.

The vaccine is understood to contain bits and pieces of genetic material obtained from two distinct Ebola virus species, i.e. Sudan and Zaire. Of these two species, the latter is the one to blame for the ongoing epidemic in West Africa.

The researchers who worked on this project explain that, although containing segments of genetic material taken from these two Ebola virus species, the vaccine they developed and tested cannot cause Ebola disease.

To introduce the Ebola genetic material into the bodies of the volunteers who took part in this investigation, the scientists used a carrier virus identified as the chimpanzee-derived adenovirus 3, otherwise known as cAd 3.

Previous investigations have shown that this carrier virus causes a common cold in primates. However, there is no evidence to suggest that it can cause illness in humans, which is precisely why the scientists used it in their experiments.

How the vaccine affected the volunteers

In a paper in the New England Journal of Medicine, NIAID researchers say that, as part of this study, they administered the experimental Ebola vaccine to 20 volunteers between the ages of 18 and 50.

The trial was carried out at the US National Institutes of Health Clinical Center in Bethesda, Maryland, they go on to detail.

After being administered the vaccine, the participants to this clinical trial were closely monitored over the course of several weeks. It's important to note that, whereas 10 of the volunteers were given a lower dose of the vaccine, the others got a higher one.

The scientists say that the experimental Ebola vaccine was well tolerated by all the volunteers. Besides, the mix was found to have triggered an immune system response in all the healthy adults who were enrolled in this study.

More precisely, it appears that the immune systems of all the volunteers all started producing Ebola antibodies some 4 weeks following inoculation. The volunteers who were injected a higher dose of the vaccine were found to have produced more such antibodies.

Interestingly enough, specific immune system cells known as CD8 T were documented in the bodies of 2 of the volunteers who received a low dose of the vaccine and 7 of the study participants who got a higher one.

This is important because, as shown by previous experiments carried out on non-human primates, these cells are especially important in fighting Ebola.

As far as side effects are concerned, researchers say that, apart from two individuals who experienced fever for a short while after inoculation, the other participants in this study did not develop any adverse effects following their being injected with the experimental vaccine.

So, what's next?

Having completed this small-scale clinical trial, NIAID scientists wish to move on to testing their experimental Ebola vaccine on larger groups of people.

They hope that, soon enough, they will be able to make the mix available to people in West Africa. The goal is to put an end to this epidemic that has until now claimed well over 5,000 victims.

“Based on these positive results from the first human trial of this candidate vaccine, we are continuing our accelerated plan for larger trials to determine if the vaccine is efficacious in preventing Ebola infection,” explains NIAID Director Anthony S. Fauci, M.D.

“The unprecedented scale of the current Ebola outbreak in West Africa has intensified efforts to develop safe and effective vaccines, which may play a role in bringing this epidemic to an end and undoubtedly will be critically important in preventing future large outbreaks,” he adds.

As explained in an animated video that made it online earlier this month, the Ebola virus kills by toying with the body's immune system and turning it into its slave. Thus, scientists say that, after entering the body, the virus moves on to infect immune cells, which it turns into Ebola factories.

Not long following infection, the virus causes internal bleeding and organ failure. Despite the fact that the scientific community has been aware of the existence of this virus for several decades now, no proper vaccines or treatments have so far been developed.

Ebola vaccine successfully tested on humans (5 Images)

Scientists test experimental Ebola vaccine on people
The vaccine was administered to a total of 20 volunteersThe vaccine contained genetic material from two distinct Ebola species
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