DEC 26, 2016 01:24 AM PST

Ebola vaccine is 100% effective after 10 days

Image Credit: Getty Images

An international group of researchers associated with the World Health Organization published its final report on the Ebola vaccine trial in Guinea, finding that the vaccine is a safe and effective way to prevent Ebola infection.

They report the vaccine is 100 percent effective at preventing Ebola when given 10 or more days prior to exposure to the deadly virus. The study findings were published in The Lancet.

“The goal was to estimate the vaccine efficacy from a phase III randomized vaccine trial,” says Ira Longini, a professor in biostatistics at the University of Florida and a key figure in the design of the Ebola vaccine trial and the analysis of its statistical data.

The 2014 Ebola virus outbreak was by far the largest and most lethal Ebola outbreak ever recorded. Transmission occurred primarily in three West African countries: Liberia, Sierra Leone, and Guinea. According to the Centers for Disease Control and Prevention, the virus infected nearly 29,000 people in the region, with more than 11,000 deaths.

The trial was called “Ebola ça suffit!” and it was the first successful phase III trial for an Ebola vaccine. Having successfully completed phase III indicates it has been tested on hundreds of subjects and proven both safe and effective.

If there’s another outbreak

Trial participants were organized into 117 clusters, of which 70 clusters received the vaccine immediately and 47 clusters received it 21 days later. Disease takes several days—even weeks—to develop following Ebola infection, yet there were zero cases among vaccines more than 10 days after any cluster received the vaccination.

Those in immediately vaccinated clusters who were not vaccinated still received protection, thanks to the trial design—known as a “ring vaccination” trial. This type of trial creates clusters around contacts of people who have contracted the pathogen, as well as contacts of contacts, since these people are at a higher risk of contracting disease. Since the immediately vaccinated participants reduced the number of infections, those ineligible for vaccination within immediate clusters benefitted from herd immunity.

According to the report, vaccinating only 52.1 percent of the participants was still 70.1 percent effective in preventing the spread of Ebola.

The vaccine is not available for sale. The WHO has collected a stockpile as a safeguard, just in case another Ebola outbreak occurs.

“We are now helping WHO replicate this experience for all emergency infectious disease threats through the Research and Development Blueprint for Action to prevent Epidemics at WHO,” Longini says. “This includes the design and analysis plans for Zika vaccine trials.”

Source: University of Florida

Original Study DOI: 10.1016/S0140-6736(16)32621-6

This article was originally published on Futurity.org.

About the Author
  • Futurity features the latest discoveries by scientists at top research universities in the US, UK, Canada, Europe, Asia, and Australia. The nonprofit site, which launched in 2009, is supported solely by its university partners (listed below) in an effort to share research news directly with the public.
You May Also Like
JUL 25, 2018
Immunology
JUL 25, 2018
T Cell Response to Ebola Virus Proteins
Killer T cells of Ebola survivors respond better to nucleoproteins, not glycoproteins, potentially influencing Ebola vaccine development....
AUG 02, 2018
Immunology
AUG 02, 2018
Chronic Infections Outsmart the Immune System
Chronic parasitic infection shown to take advantage of a mechanism to sustain infection and induce death of white blood cells essential to immune response....
SEP 07, 2018
Health & Medicine
SEP 07, 2018
What's Behind the Massive Measles Outbreak in Europe?
Measles is a disease that many believe was eradicated years ago. That's true, to a point, but like a bad penny, it's back. In the United States, th...
SEP 11, 2018
Immunology
SEP 11, 2018
Oops! I Broke My DNA
Innate Immune System, DNA Damage and Repair...
OCT 03, 2018
Immunology
OCT 03, 2018
Natural Killers for HIV Vaccine
A team of researchers from Duke Human Vaccine Institute has recently published their work regarding the interplay of natural killer cells (NK cells) and broadly neutralizing antibodies (bnAbs...
OCT 08, 2018
Immunology
OCT 08, 2018
Natural Killer Cells to Aid in Cancer Therapy
Researchers utilize nanoparticles to stimulate NK cells that induce tumor cells to express PDL1, a protein involved in immune response messaging...
Loading Comments...