A third producer of oral cholera vaccine has been approved that is expected to provide 3 million doses in 2016, doubling the world's stockpile against a disease that can kill within hours, Reuters quoted the World Health Organization as saying on Friday.

EuBiologics, a South Korea-based producer, joins Shantha Biotechnics of Sanofi Pasteur as a pre-qualified supplier, WHO expert Stephen Martin told a news briefing. The third producer, which currently does not have doses in the stockpile, is Sweden's Crucell, he said.

"It has future potential in the next 3-4 years for a much greater increase in vaccine production," he said. A vaccine campaign will begin in Haiti this month, targeting some 240,000 people, he added.