Ebola vaccines provide immune responses after one year

March 14, 2017, The JAMA Network Journals
The Ebola virus, isolated in November 2014 from patient blood samples obtained in Mali. The virus was isolated on Vero cells in a BSL-4 suite at Rocky Mountain Laboratories. Credit: NIAID

Immune responses to Ebola vaccines at one year after vaccination are examined in a new study appearing in the March 14 issue of JAMA.

The Ebola virus vaccine strategies evaluated by the World Health Organization in response to the 2014-2016 outbreak in West Africa included a heterologous primary and booster vaccination schedule of the adenovirus type 26 vector vaccine encoding Ebola virus glycoprotein (Ad26.ZEBOV) and the modified vaccinia virus Ankara vector vaccine, encoding glycoproteins from Ebola, Sudan, Marburg, and Tai Forest viruses nucleoprotein (MVA-BN-Filo). These vaccines both used a 'viral-vector' approach, where a benign virus is modified to safely express key proteins of the target virus, in this case Ebola. This schedule has been shown to induce immune responses that persist for eight months after primary immunization, with 100 percent of vaccine recipients retaining Ebola virus glycoprotein-specific antibodies. A vaccine that provides durable immune responses is important in maintaining sustained protection against disease, both during outbreaks and outside of an outbreak for at-risk populations.

Matthew D. Snape, M.D., of the University of Oxford, United Kingdom, and colleagues conducted a trial that was performed in Oxford and enrolled healthy participants ages 18 to 50 years, who were randomized to four groups, each with 18 participants (3 placebo and 15 active vaccine).

Of 75 active vaccine recipients, 64 attended follow-up at day 360. No serious adverse events were recorded from day 240 through day 360. All of the active vaccine recipients maintained Ebola virus-specific immunoglobulin G responses at day 360. To the authors' knowledge, this is the longest duration follow-up for any heterologous primary and booster Ebola vaccine schedule.

"Immunity after heterologous primary and booster vaccination with Ad26.ZEBOV and MVA-BN-Filo persisted at 1 year. Although no correlate of protection has yet been established, Ebola glycoprotein-specific antibodies appear to play an important role in immunity. A strategy of preemptive use of an AD26.ZEBOV followed by MVA-BN-Filo immunization schedule in at-risk populations (where durability of is likely to be of primary importance) may offer advantages over reactive use of single-dose regimens," the authors write.

The researchers note that a limitation of the study is that it was conducted in a European population. "Immune responses may differ in a sub-Saharan African population; these are being assessed in this region.

Explore further: Study examines safety, immune response of candidate Ebola vaccines

More information: JAMA, DOI: 10.1001/jama.2016.20644

Related Stories

Study examines safety, immune response of candidate Ebola vaccines

April 19, 2016
In a study appearing in the April 19, 2016 issue of JAMA, Matthew D. Snape, F.R.C.P.C.H., M.D., of the University of Oxford, United Kingdom, and colleagues conducted a phase 1 trial to evaluate the tolerability and immunogenicity ...

Two-vaccine Ebola regimen shows promise in early-stage clinical trial

April 19, 2016
An immunization regimen using two Ebola vaccine candidates was safe and well-tolerated and induced an immune response in healthy adult volunteers in a Phase 1 clinical trial. Results from the study are described in the April ...

Recombinant type-5 vector-based ebola vaccine safe

December 27, 2016
(HealthDay)—For healthy adults from Sierra Leon, the recombinant type-5 vector-based Ebola vaccine is safe and immunogenic, according to a study published online Dec. 21 in The Lancet.

Stopping Ebola in its tracks: which vaccine will do it?

December 23, 2016
Forty years after emerging in what is today the Democratic Republic of Congo, the Ebola virus may finally have met its match in a vaccine which could be "up to 100 percent effective", according to its makers.

New study highlights effectiveness of a herpesvirus CMV-based vaccine against Ebola

February 15, 2016
As the latest in a series of studies, researchers at Plymouth University, National Institutes of Health and University of California, Riverside, have shown the ability of a vaccine vector based on a common herpesvirus called ...

Ebola vaccine trial begins in Senegal

July 15, 2015
A trial to evaluate an Ebola vaccine has begun in Dakar, Senegal, after initial immunisations started at the Jenner Institute, Oxford University. The announcement comes as a conference in Oxford discusses the global response ...

Recommended for you

Novel molecular target to prevent scarring of the lung blood vessels identified

June 13, 2018
Pulmonary arterial hypertension, a severe form of cardiopulmonary disease in which the arteries that transport blood from the heart to the lungs become thickened, constricted, and scarred, is a disease for which there is ...

Fast-acting cholera vaccine could curb outbreaks

June 13, 2018
A tricked-out cholera vaccine starts protecting against the deadly disease within a day, experiments in rabbits suggest. The rapid protection offered by this designer vaccine may one day limit the spread of cholera outbreaks, ...

Lineage of TB traced and compared to early human migration

June 13, 2018
A team of researchers from the University of Wisconsin, the University of Iowa and the Norwegian Institute of Public Health has carried out genetic studies of tuberculosis to learn more about its lineage and to compare it ...

Finally, hope for a syphilis vaccine

June 12, 2018
Despite efforts to eradicate it, syphilis is on the rise. Until now, most health agencies focused on treating infected people and their sex partners but new discoveries may make a vaccine possible, UConn Health researchers ...

How to slow down Ebola—Virologists use 'genetic trees' to evaluate intervention strategies

June 12, 2018
The phylogenetic tree of the 2013-2016 Ebola epidemic doesn't just reveal how the Ebola virus was able to evolve—it also reveals which events and preventive measures accelerated or slowed down its spread. These findings ...

Small children and pregnant women may be underdosed in current malaria regimen

June 12, 2018
Current recommended dosing regimens for the most widely used treatment for uncomplicated Plasmodium falciparum malaria may be sub-optimal for the most vulnerable populations of patients, according to a study published this ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.