DEC 26, 2016 1:24 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
MAR 20, 2020
Neuroscience
MAR 20, 2020
The Little Things Matter: The Mental Impact of Social Distancing
Image: Metropolitian State University of Denver The COVID-19 pandemic has caused social interactions, resources, and mos ...
MAR 28, 2020
Drug Discovery & Development
MAR 28, 2020
FDA Approves 5-Minute Coronavirus Test
In recent weeks, the US has struggled to supply enough tests to detect the coronavirus. Now, however, this may change th ...
MAR 28, 2020
Drug Discovery & Development
MAR 28, 2020
Could the Blood of Coronavirus Survivors Save Lives?
As the search for a treatment for coronavirus continues, a perhaps obscure-sounding candidate has begun to make headline ...
APR 17, 2020
Neuroscience
APR 17, 2020
Anti Vaxxers More Paranoid than Average Person
Researchers from Texas Tech University have found that anti-vaxxers (those who deny the efficacy of vaccines) are more p ...
APR 20, 2020
Immunology
APR 20, 2020
Making Sense of the T Cell Response Spectrum
T cells go through a sort of “training” process throughout life, and scientists recently discovered that the ...
MAY 06, 2020
Drug Discovery & Development
MAY 06, 2020
Breakthrough in Antibody Treatment for COVID-19
Israeli scientists have announced significant progress in isolating an antibody that may be effective in treating those ...
Loading Comments...