Public health officials had been hopeful that an experimental vaccine could help curb the spread of the outbreak. But, for that to happen, response teams must be able to identify people who have been in contact with Ebola patients. Persistent violence in the outbreak zone has made that hard to do.
More than half of the recently detected cases haven’t been on lists of contacts. And even retrospective detective work is failing to piece some of these people into the transmission chain, the World Health Organization acknowledged.
“We have a number of indicators right now showing that our ability to quickly detect cases and follow up on their contacts has been seriously challenged by the safety issues,” said Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota, who has been tracking the epidemic.
Vaccine, he said, “can’t be given to people you don’t know exist.”
The severe insecurity problems in North Kivu, the province in northeastern DRC where Ebola is spreading, are throwing up major challenges for the outbreak response. There have been repeated attacks by rebel forces on Beni, the current Ebola hot spot, stymying efforts to track Ebola patients and their contacts.
The further behind the virus that the response teams get, the more difficult it will be to use the still-unlicensed vaccine, made by Merck, to its maximum effect, experts acknowledged.