KINSHASA, Democratic Republic of Congo — Officials began vaccinating health workers and others against Ebola on Monday in Bikoro, where an outbreak of the disease was declared at the beginning of May.

Congo’s health minister, Oly Ilunga, traveled to oversee the vaccinations of at least 10 people in Bikoro, where at least five of the 12 deaths tied to Ebola have been reported.

The director of the Bikoro Hospital, Dr. Serge Ngalebato, said he and other health officials had been vaccinated for protection so they could treating patients with the disease.

“We who are on the front lines of caring for the sick,” Dr. Ngalebato said in a telephone interview. “We are reassured.”