The secretive state did not provide proof, and the claim is likely to provoke widespread scepticism. The official Korean Central News Agency said scientists developed Kumdang-2 from ginseng and other ingredients. North Korea trumpeted the same drug during deadly bird flu outbreaks in 2006 and 2013. The North's claim comes as rival South Korea fights an outbreak of Mers that has killed two dozen people and sickened more than 160 since last month. There is no vaccine for the disease.