The WHO said it had sent 300 body bags for safe burials in affected communities, a possible indication of how big it expects the outbreak to be.
African Union (AU) sent today a health team to the Democratic Republic of Congo (DRC) to monitor the situation and the country " s required level of support to stop Ebola outbreak.
The Ebola outbreak in the Democratic Republic of Congo has spread to the northwest city of Mbandaka, the World Health Organization said, adding it will convene an Emergency Committee on Friday to consider its global risks. He said epidemiologists are working to identify additional contacts to the 500 already identified.
It is the ninth time Ebola has been recorded in Congo since the disease made its first-known appearance near its northern Ebola river in the 1970s.
Before Wednesday's announcement, there had been only two cases of the virus confirmed by lab tests.
Until now, all the confirmed Ebola cases were reported from Bikoro health zone, which is also in Equateur Province but at a distance of almost 150 km from Mbandaka.
According to the country's Ministry of Health, the vaccine arrived on Wednesday, after it declared the outbreak in the northwest region near Congo-Brazzaville on May 8.
Till now, Congo has reported 23 deaths among the 42 suspected, probable and confirmed cases.
The first batch of 4,000 doses of vaccine was already being flown to Kinshasa, and the World Health Organization plans to send a second batch of 4,000 doses in coming days, World Health Organization spokesman Tarik Jasarevic said.
The 2014-16 West Africa outbreak, which killed 11,300 people, was particularly deadly because it spread to the capital cities of Guinea, Sierra Leone and Liberia.
Out of the 20 persons died in DRC, 3 are health workers, Director of the Center John Nkengasong said.