The World Health Organization announced Sunday that a vaccination campaign for frontline workers and people infected with Ebola has begun in the Democratic Republic of Congo.

Sept. 14 (UPI) -- The World Health Organization announced Sunday that a vaccination campaign for frontline workers and people infected with Ebola has begun in the Democratic Republic of Congo.

An initial 400 doses of the Ervebo Ebola vaccine from the country's 2,000 stockpile have been delivered to Bulape in the DRC's central province of Kasai, that borders Angola, where officials are attempting to clamp down on an outbreak of the deadly and contagious Ebola virus, the WHO said in a statement.

Additional doses of the vaccine will be delivered in the coming days, it said.

The vaccine doses are being distributed under what the WHO called a "ring" strategy that first vaccinates individuals at highest risk after coming into contact with a confirmed patient.

Prof. Mohamed Yakub Janabi, the WHO's regional director for Africa, published images of the vaccination campaign on social media, stating "intense efforts are underway to stop the #Ebola outbreak in #DRC."

"Together with #DRC health authorities & partners, we are working round the clock to stop this outbreak," he said in a second statement to X.

The vaccination campaign was launched to battle an outbreak in the Bulape health zone. The DRC's Health Ministry said in a statement on Tuesday that there have been at least 16 deaths, including four health workers, amid the recent outbreak in Bulape. The U.S. Centers for Disease Control and Prevention said the DRC has detected 63 suspected cases.

The DRC's health ministry declared the DRC's 16th recorded outbreak of Ebola on Sept. 4. The virus was first discovered in the DRC in 1976.

The WHO said it was alerted by the health ministry to suspected cases in the country on Sept. 1, and has assessed the overall public health risk of the outbreak to the nation as high, moderate for the region and low at the global level.

Its International Coordinating Group on Vaccine Provision has approved shipping around 45,000 additional Ebola vaccine doses to the DRC, where so far 48 of its experts in disease surveillance, clinical care and other areas have been deployed.

The last outbreak of the disease in the DRC was reported on Aug. 15, 2022 in Beni City, North Kivu province. One case was reported, who later died. The outbreak was declared over on Sept. 27 of that year.

The last outbreak in Bulape was in 2007.