KINSHASA, Congo -- Officials began vaccinating health workers and others on Monday in Bikoro, where Congo's current Ebola outbreak was first declared at the beginning of May.

Congo's Health Minister Oly Ilunga traveled to oversee the Ebola vaccinations of at least 10 people in Bikoro, where at least five of 12 Ebola deaths have happened.

Bikoro Hospital director Dr. Serge Ngalebato said he and other health officials were vaccinated for protection when treating Ebola patients.

"We who are on the front lines of caring for the sick. We are reassured," he told The Associated Press by telephone. Monday's vaccinations included three doctors at Bikoro Hospital, two health experts, two nurses, one representative of women in the community and one pygmy representative, he said.

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The procedure, which is voluntary, will take time and follow up to make sure there is a positive response, Ngalebato said.

Congo's vaccination campaign, which began in Mbandaka last week, is targeting more than 1,000 health workers and contacts of the sick in three health zones.

More than 360 people were vaccinated before Monday, said health ministry spokeswoman Jessica Ilunga.

As of Monday Congo updated that there were 54 cases of hemorrhagic fever: 35 confirmed Ebola cases, 13 probable and six suspected.

Amid worries of the spread of Ebola, several schools in the Iboko health zone, about 180 kilometers (112 miles) southeast of Mbandaka, have been closed, according to reports by U.N.-backed Radio Okapi.

Many residents in one of the Iboko localities told Radio Okapi that they prefer to stay at home to avoid infection, following the death of a woman who had Ebola in the nearby Bobala area.

One resident said that what they first thought were rumors were becoming reality with the death and that they were very scared to interact. Four confirmed Ebola deaths have taken place in the Iboko health zone, according to Congo's health ministry.

Several heads of schools in the area also said they would suspend school activities to protect the children.

This is Congo's ninth Ebola outbreak since 1976, when the hemorrhagic fever was first identified.

There is no specific treatment for Ebola. Symptoms include fever, vomiting, diarrhea, muscle pain and at times internal and external bleeding. The virus can be fatal in up to 90 percent of cases, depending on the strain.

Ebola is initially transmitted to people from wild animals, including bats and monkeys. It is spread via contact with the bodily fluids of those infected, including the dead.