The Latest on the Ebola Vaccine

Experimental Ebola vaccine highly effective in West African trial

(RxWiki News) The recent West African epidemic has intensified the search for an effective Ebola vaccine. And researchers are now saying they may be one step closer to finding one.

Researchers from the University of Florida (UF) and the World Health Organization (WHO) recently tested an experimental Ebola vaccine in West Africa using an innovative technique called ring vaccination, a method first used to help eradicate smallpox in the 1970s. This method involves vaccinating the person who had contact with the disease as well as his or her close contacts.

The experimental Ebola vaccine was hugely successful — resulting in an estimated 100 percent efficacy of the vaccine against the virus. Additionally, researchers say this approach could provide a new way to respond to outbreaks of other emerging pathogens, including Zika virus.

Study co-author Ira Longini, PhD, said in a press release, "This type of analysis is a very robust design. It worked for the Ebola vaccine, and could work for the Zika vaccine, or any other emerging threat we might see." Dr. Longini is the director of the UF Center for Statistics and Quantitative Infectious Diseases.

He continued, "Now, we want to make the point that we can almost certainly contain future Ebola outbreaks, and that we will probably have a new paradigm and tool for dealing with new outbreaks of whatever emerges in the future."

Ebola virus disease (EVD) is a severe, often fatal illness transmitted from animals to humans. Once a human is infected, he or she can spread the virus to others through direct contact with bodily fluids like blood and saliva.

EVD kills about 50 percent of those infected. While there is no known treatment or cure for EVD, at least two other vaccines are currently being tested, according to WHO.

For their study, Dr. Longini and colleagues administered the vaccine to 7,651 people in Guinea, West Africa.

Close contacts of the infected person, who might include family members, health care workers or classmates, were assigned to one of two groups. The first group received the vaccine as soon as they were exposed to EVD. The second group received the vaccine seven days later.

In the immediate vaccination group, no cases of EVD developed. In the delayed group, 16 out of 3,528 people developed EVD.

Researchers said they still don't know whether the immunity to EVD provided by the vaccine will last. The trial is still ongoing.

The initial trial was published in the August 2015 issue of The Lancet. The interim results of the trial were presented Feb. 12 at the American Association for the Advancement of Science's annual meeting.

The World Health Organization, the Wellcome Trust, the Research Council of Norway and the Canadian Government, among others funded this research.

Conflicts of interest information was not available at the time of publication.

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Review Date: 
February 16, 2016
Last Updated:
February 17, 2016