Rwanda said Sunday it had begun administering vaccine doses against the Marburg virus to try to combat an outbreak of the Ebola-like disease in the east African country, where it has so far killed 12 people.

“The vaccination is starting today immediately,” Health Minister Sabin Nsanzimana said at a news conference in the capital Kigali.

He said the vaccinations would focus on those “most at risk, most exposed health care workers working in treatment centers, in the hospitals, in ICU, in emergency, but also [in] the close contacts of the confirmed cases.”

The country has already received shipments of the vaccines including from the Sabin Vaccine Institute.

Rwanda’s first outbreak of the viral hemorrhagic fever was detected in late September, with 46 cases and 12 deaths reported since then. Marburg has a fatality rate as high as 88%.

Marburg symptoms include high fever, severe headaches and malaise within seven days of infection and later severe nausea, vomiting and diarrhea.

It is transmitted to humans by fruit bats and then spreads through contact with the bodily fluids of those infected. Neighboring Uganda has suffered several outbreaks in the past.

“We believe that with vaccines, we have a powerful tool to stop the spread of this virus,” the minister said.