Leading drugmakers plan to work together to speed up the development of an Ebola vaccine and hope to produce millions of doses for use next year.

U.S. firm Johnson & Johnson said on Wednesday that it aims to produce at least 1 million doses of its two-step vaccine next year and has already discussed collaboration with Britain's GlaxoSmithKline, which is working on a rival vaccine.

The economics of an Ebola vaccine are still unclear but drug companies with an eye on their reputations are under pressure to respond to the major international health crisis now ravaging one of the poorest corners of Africa.

J&J's head of research Paul Stoffels said it was important to have several experimental vaccine candidates in development, since it is not clear which ones will work, but resources could in future be focused on one clear winner.

GSK's chief executive Andrew Witty told reporters on Wednesday that a meeting of experts in Geneva this week would discuss ways to ensure that all companies, including those with no direct involvement in the Ebola work, pulled together to help remove supply bottlenecks.

There is currently no proven vaccine against the deadly disease and drug companies have been wary in the past of pouring resources into Ebola since previous outbreaks have been small. As a result much of the research effort to date has been driven not by concerns about sporadic outbreaks in Africa but by fears in the West that Ebola might become a bioterror weapon.

FRONTLINE HEALTH WORKERS

Clinical tests on GSK's vaccine and another from NewLink Genetics are under way, while human tests on J&J's vaccine will start in January.

The World Health Organization (WHO) hopes that tens of thousands of people in West Africa, including frontline healthcare workers, can start receiving Ebola vaccines from January as part of large-scale clinical trials.

The first doses of GSK's Ebola vaccine are expected to be ready late this year. "It will give WHO and other agencies a useful tool," Witty said, adding that the GSK product was likely to be the first vaccine to be deployed on a limited basis.

Witty and Stoffels said they had talked several times in recent days about collaboration, including swapping ideas on production and vaccine development. "It might even be that we have to combine their vaccine with ours," Stoffels said.

J&J expects the accelerated work on its Ebola vaccine, which has been helped by recent advances in technology, would yield 250,000 doses by May.

The U.S. company plans to test its vaccine for safety and immune response in healthy volunteers in Europe, the United States and Africa from early January, having committed up to $200 million to accelerate the program.

BOOST FOR BAVARIAN NORDIC

West Africa's Ebola outbreak began in March and has killed more than 4,500 people, most of them in Liberia, Sierra Leone and Guinea, according to the WHO. Outbreaks in Senegal and Nigeria have been declared over by the WHO and there have been a handful of cases in Spain and the United States.

The J&J vaccine was discovered in collaboration with the U.S. National Institutes of Health (NIH) and includes technology from Denmark-based Bavarian Nordic, which will now receive a cash injection from the American healthcare company.

The total potential deal value for Bavarian Nordic could be more than $187 million, including up-front payments, milestone payments based on product progress, a supply contract and the purchase by J&J of shares in the Danish biotech business.

Bavarian Nordic's share price jumped 23 percent to 185 Danish crowns after the announcement of J&J's plans.

J&J has simplified and fast-tracked its vaccine program in the light of the world's worst Ebola outbreak.

It had been working to develop a vaccine against both the Zaire and Sudan strains of Ebola, as well as a related condition called Marburg disease. However, it is now also developing a vaccine targeting only the Zaire strain behind the current epidemic, which should yield results faster.

PROMISING SIGN

Although the safety and effectiveness of J&J's and other experimental vaccines has yet to be proven, they have provided good protection against the Zaire strain of Ebola when tested on macaque monkeys, which is seen as a promising sign that they are likely to work in humans.

Like a number of experimental vaccines against various diseases, J&J's vaccine uses a common cold virus, called an adenovirus, to carry its payload.

Immunization with the J&J vaccine, which was developed by its Crucell unit in the Netherlands, consists of two injections: one to prime the immune system and a second to boost the response. In contrast, researchers are testing a single shot of GSK's vaccine.

(1 US dollar = 5.8566 Danish crowns)