An experimental vaccine to contain Ebola disease outbreaks in the Democratic Republic of Congo (DRC) is showing promising results, a new study released by the World Health Organization (WHO) on Friday said. 

The vaccine showed an efficacy of 97.5 percent.  Around  93,965 people at risk of the disease were vaccinated in August last year. Only 71 of them developed Ebola. 

Of the 71, nearly 56 people developed symptoms in less than 10 days after getting the vaccination shot. It takes around 10 days for the vaccine to build immunity against the virus. 

The other 15 people contracted the virus ten days after the vaccination. 

“No deaths were reported among vaccinees who developed Ebola with onset 10 or more days after vaccination. These early results confirm previous observations of high efficacy of (rVSV-ZEBOV-GP) Ebola vaccine against the disease,” the study said. 

The health officials are adopting, the ring vaccination strategy—vaccinating only those who are most likely to be infected—to test the Ebola vaccine. The procedure was first adopted to prevent the spread of smallpox. 

“The ring vaccination strategy is a highly efficient delivery strategy for Ebola vaccines during outbreaks,” the WHO maintained.  

Frequent Ebola outbreaks have caused a significant health concern globally. Around 1,206 confirmed and probable cases of Ebola virus disease have been reported during the recent outbreak in the Democratic Republic of the Congo (DRC). 

The virus has claimed scores of lives in the North Kivu and Ituri provinces of the country.  

Fearing a major Ebola epidemic, the U.S. European Union, Russia, and China are developing Ebola vaccines. At present more than 15 vaccines are at various stages of testing. 

Pharmaceutical companies have committed to ramping up the production capacity once the vaccine passes crucial tests, the WHO statement last year said. “This could be the fastest vaccine roll-out in history.”

Meanwhile, despite mounting cases of Ebola in DRC, top officials of WHO on Friday refused to declare the outbreak as a global health emergency. 

“It was the view of the Committee the ongoing Ebola outbreak in North Kivu, and Ituri provinces of the Democratic Republic of the Congo does not constitute a Public Health Emergency of International Concern (PHEIC),” said Robert Steffen, chair of the WHO-convened committee on emergency declaration said.