The UN World Health Organization (WHO) hopes to begin a mass vaccination drive later this week to head off the advance of Ebola in the Democratic Republic of Congo.

The government of the DRC has formally asked to use an experimental vaccine called V920 under development by Merck, which agreed with the plan.  WHO has 4,300 doses stockpiled in Geneva, Switzerland while Merck has 300,000 stashed away in the United States.

"Everything is ready for the vaccine.  They want it," said WHO director-general Tedros Adhanom Ghebreyesus.

Health officials declared an outbreak in the DR Congo town called Bikoro on 8 May.  Only two cases have been confirmed, but there are 32 to 39 suspected, probable or confirmed cases of the disease, including 18 deaths since 4 April.  And there are other suspected cases in a village called Ikoko-Impenge, about 65 kilometers away.  

One of the big fears is the location of Bikoro, which on a map seems fairly remote.  But it sits on a port along on Lake Tumba, which feeds into the Congo and Ubangi rivers - major waterways that connect to several large centers.  The DRC capital city Kinshasa with its 11.5 million residents is to the south; so is Brazzaville, population 1.9 million.  Mbandaka, with a population of about 1 million people, also connects to Bikoro by waterway.  And the Central African Republic's capital Bangui, population 800,000, is to the north.

Despite these inter-African connections, Bikoro is difficult for international health workers to reach.  And they must establish a "cold chain" to transport the vaccines from the capital to the frontlines because the vaccine must be kept at sub-zero temperatures until it is ready to be used.  The refrigeration kit began arriving in country over the weekend.  The vaccines could be shipped as early as mid-week.

After that, the teams will begin vaccinating healthcare workers and more than 300 people believed to have come into contact with Ebola patients.

Ebola is a highly contagious virus that causes Ebola Virus Disease, characterized by hemorrhagic fever and death in 25 to 90 percent of cases.