First-ever Ebola vaccine shows 'promise' -- now what?

The World Health Organization ran clinical trials for an Ebola virus vaccine in Guinea. The storage devices shown here use jet fuel to keep the vaccines at a temperature of minus 60 degrees Celsius. Photo by S. Hawkey/WHO

A vaccine for the Ebola virus – the first of its kind in the disease's 40-year recorded history – shows promise in trials in Guinea, according to a report released Friday in the medical journal Lancet.

"It could be a game-changer, because previously there was nothing against Ebola," Dr. Marie-Paule Kieny, assistant director-general for health systems and innovation at the World Health Organization, told reporters in Geneva. It's "promising" but results still need to be confirmed by the scientific community, she said.

Doctors Without Borders, which helped run the trials in Guinea, called it a "breakthrough."

"Too many people have been dying from this extremely deadly disease, and it has been very frustrating for healthcare workers to feel so powerless against it. More data is needed to tell us how efficacious this preventive tool actually is, but this is a unique breakthrough," the group's Medical Director Bertrand Draguez said in a statement.

An all-out search for a vaccine was launched after a widespread Ebola outbreak hit West Africa. The disease, which surged in the spring of 2014 primarily in Guinea, Liberia and Sierra Leone, has infected about 27,800 people and killed 11,300, according to the World Health Organization's latest figures.

The new vaccine, called VSV-EBOV, was first discovered by the public health agency of Canada. Drug manufacturer Merck has acquired the rights to develop it.

In trials that started in Guinea in March 2015, the vaccine was tested in "rings" of people in contact with those infected with Ebola, Kieny said.

Some rings of people were vaccinated immediately. Other rings of contacts were vaccinated three weeks later, and the results of both groups were compared.

In the rings that were vaccinated immediately, none of the 2,014 people in the trial developed the disease after 10 days of being vaccinated.

Of the 2,380 people in the control group — those who had the delayed vaccine — 16 developed Ebola.

The vaccine appears to be so effective that WHO is going to stop delaying the vaccinations, as it was doing in the control groups, and will start vaccinating children and young adults in light of the new data, Kieny said.

The vaccine still needs to be registered, which will take a few weeks or months, but the hope is the vaccine will be stockpiled and ready to use the next time there is an Ebola outbreak, she said. "Not if, when, there will be a new outbreak, because there is no doubt there will be new outbreaks."

Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases at the National Institutes of Health, describes the significance of the findings on Friday's PBS NewsHour.

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