World Health Organisation warns that it may be impossible to use a vaccine to deal with the new Ebola outbreak in the Democratic Republic of Congo, which has spread over 10 kilometers and may have started in May, said a senior WHO official said Thursday .

Sponsored Ad

Officials have not yet confirmed the Ebola strain, which killed 20 people and killed four others, including two health workers. It could be the Zaire, Sudan or Bundibugyo strain, said WHO Chief of Emergency Response Peter Salama.

If it is the Zaire strain, the Merck vaccine used in the last outbreak may be an option, otherwise the situation will be much more complex "and we may not have any vaccine options," he said. Reuters at WHO headquarters in Geneva