During the Ebola epidemic in Africa, which began unnoticed in late 2013 and spread across the continent, over 28,000 people were affected and over 11,000 were killed. However, it looks like this is the last time a large Ebola outbreak will ever happen after scientists developed a vaccine that has proven to be effective in an invasive trial with over 5,000 test subjects.
"We were able to estimate the efficacy of the vaccine as being 100 percent in a trial with more than 5,000 people," Ira Longini, a biostatistician at the University of Florida who helped test the vaccine, told NPR. "It's very unusual to have a vaccine that protects people perfectly."
The Ebola vaccine works within four to five days, so it could potentially be given to someone who was exposed to the disease but hasn't yet developed it or shown symptoms. Ten days after vaccination, not a single trial subject developed Ebola. Of course, 100% seems a bit extreme, but NPR notes that by comparison, the flu vaccine was approximately 50% effective as recently as last year.
"While these compelling results come too late for those who lost their lives during west Africa's Ebola epidemic, they show that when the next Ebola outbreak hits, we will not be defenseless," lead author Dr. Marie-Paule Kieny told The Guardian.
The trial began in the coastal region of Basse-Guinée in 2015, according to The Guardian:
"When a new case of Ebola was diagnosed, the teams offered vaccination to everybody who had been in contact with that person in the previous three weeks, from family to friends and neighbors...At first, adults were randomly assigned to get the vaccine immediately or three weeks later, but when it became clear that the vaccine was protecting most people, everybody was offered immediate vaccination, including children."
Out of the 5,837 who received the disease, not a single case of Ebola was reported after 10 days. "This novel and historic trial, conducted under the most difficult of circumstances, has demonstrated that the rVSV-ZEBOV vaccine is safe and effective," co-author John Edmunds told The Guardian. "When Ebola strikes again we will be in a much better position to offer help to affected communities, as well as protect the brave volunteers who help control this terrible disease."
(H/T NPR, The Guardian)
