The Democratic Republic of Congo is preparing to roll out an Ebola vaccine, including as part of a clinical trial testing whether it protects against the Bundibugyo species of the virus, which is driving the country's current outbreak. The move comes as the World Health Organization warns that infections are growing "exponentially" across an area of northern and eastern DR Congo larger than France, with the outbreak now the deadliest in the country's history and the second-worst globally.

Close to 2,500 people have died since the outbreak was declared three months ago, with half of those deaths occurring in just the last 20 days, according to WHO Ebola co-ordinator Julien Harneis. The Ervebo vaccine, previously proven only against the Zaïre species, will be trialled using 20,000 doses, while 50,000 further doses go to front-line health workers; the response has been complicated by initial misdiagnoses, conflict in the region, and new travel restrictions imposed by the M23 rebel group after two people tested positive in territory it controls.