Why the world needs more than one Ebola vaccine

A World Health Organization (WHO) worker administers a vaccination during the launch of a campaign aimed at beating an outbreak of Ebola in the port city of Mbandaka, Democratic Republic of Congo May 21, 2018. REUTERS/Kenny Katombe

LONDON (Reuters) - - In the life-and-death race to make the first effective vaccine against Ebola, one company - Merck - seems bound to win.

But others drugmakers, such as Johnson & Johnson and GlaxoSmithKline , are also in the running - and must stick with it even though they are unlikely to make a profit, experts say, because the world needs more than one Ebola vaccine.