Tens of thousands of doses would be given, starting with health workers

Breakthrough close: Dr Marie-Paule Kieny, World Health Organisation assistant director general, said trials are planned or underway for two an Ebola vaccine

An Ebola vaccine breakthrough could be just weeks away, a top World Health Organization (WHO) official has announced.

Dr Marie-Paule Kieny, an assistant director general for WHO, said that an experimental version of the vaccine could be ready for mass distribution in Africa early next year if current trials are successful.

She said the trials planned or underway in Europe, Africa and the U.S. are being accompanied by a push among governments for immediate 'real-world use' of an approved Ebola vaccine.

Speaking to reporters in Geneva today Dr Kieny revealed that, if the vaccines are deemed safe, tens of thousands of doses would be used in a West African trial in January.

She said there are two leading candidates for a vaccine.

One of them, developed by the U.S. National Institutes of Health and GlaxoSmithKline from a modified chimpanzee cold virus and an Ebola protein, is in clinical trials in the U.K. and in Mali. It will be used in clinical trials in Lausanne, Switzerland, by the start of February.

The second front-runner, developed by the Public Health Agency of Canada and known as VSV-EBOV, has been sent to the U.S. Walter Reed Army Institute of Research in Maryland for testing on healthy volunteers, with results expected by December.

The next stage would be to test it more broadly, including among those directly handling Ebola cases in West Africa.

Meanwhile, the organization's emergency committee on Ebola will meet tomorrow to review the scope of the outbreak and whether additional measures are needed.

'This is the third time this committee will meet since August to evaluate the situation,' WHO spokeswoman Fadela Chaib told a news briefing.

'Much has happened, there have been cases in Spain and the United States, while Senegal and Nigeria have been removed from the list of countries affected by Ebola.'

If tests currently underway show the experimental vaccines are safe for humans, a large-scale trial could be rolled in Africa as early as January, Dr Kieny said

WHO's emergency committee on Ebola will meet tomorrow to review the scope of the outbreak and whether additional measures are needed to halt the spread of the deadly virus in West Africa

The Ebola virus has already claimed more than 4,500 victims, according to the WHO

The 20 independent experts, who declared that the outbreak in West Africa constituted an international public health emergency on August 8, can recommend travel and trade restrictions.

The committee has already recommended exit screening of passengers from Guinea, Liberia and Sierra Leone.

Ms Chaib also promised a thorough public audit of the agency's early missteps in responding to the Ebola outbreak that has already killed over 4,500 people.

Yesterday, Liberian President Ellen Johnson Sirleaf claimed that the international community's initial reaction to the Ebola outbreak was 'inconsistent and lacking in clear direction or urgency'.

Tens of thousands of doses of an experimental vaccine could be ready for distribution in Africa by January if testing currently underway show that it is safe for humans

Health workers such as these volunteer nurses from Germany's Red Cross, pictured being trained in Ebola protection measures before being deployed in West Africa, would be among the first be given a vaccine when it is approved

Yesterday, Liberian President Ellen Johnson Sirleaf claimed that the international community's initial reaction to the Ebola outbreak was 'inconsistent and lacking in clear direction or urgency'

She said that although the world had now woken up to the global health risk posed by the epidemic, the outbreak still risks unleashing an economic catastrophe that will leave a 'lost generation' of West Africans.

'We all have a stake in the battle against Ebola,' President Johnson Sirleaf said in an open letter read on the BBC World Service.