The World Health Organisation's director-general says instability, high population density and large displacement in Democratic Republic of Congo's east mean the response to the nation's tenth Ebola virus outbreak must be stronger than ever before.
Dr Tedros Adhanom Ghebreyesus spoke in Beni city, where an Ebola response centre has been established. He joined DRC's health minister, Dr Oly Ilunga Kalenga, in overseeing vaccinations that began this week.
On Saturday they will visit Mangina village, where the outbreak was declared August 1.
The Ministry of Health says 44 cases have been reported, with 17 of them confirmed as Ebola, including 10 deaths.
WHO says more than 3 000 doses of the Ebola vaccine are available in DRC.
The country's east is home to dozens of rebel groups fighting for control over the mineral-rich region.