Ebola is a deadly virus, one that has been plaguing the Democratic Republic of the Congo (DRC) this past year. The virus has killed some 2,000 people since it broke out last year and threatens to kill many more if the outbreak isn’t quelled.

The good news is that for the first time ever, a vaccine for Ebola has been approved by European regulators and is already being used to fight the virus. Merck, the US pharmaceutical company behind the vaccine, has provided shots of the vaccine to hundreds of thousands of people in the DRC, including more than 60,000 health-care workers in the DRC and several neighboring countries.

Although several other vaccines against Ebola — a hemorrhagic fever that causes severe diarrhea, vomiting and bleeding — are in development, Merck’s is the only one that has been tested during an outbreak, in which it was shown to be highly effective at preventing infection. Hopefully, it continues to be effective and can help to wipe out the virus entirely.