The Bill and Melinda Gates Foundation has pledged $5.7m towards a programme to increase production of experimental Ebola treatments in Guinea and other affected countries.

The programme will focus on treatments derived from the blood of survivors.

The foundation also said the grant would be used to evaluate new experimental drugs.

More than 5,000 people have died in the current Ebola outbreak - almost all of them in West Africa.

There is currently no licensed treatment or vaccine for the Ebola virus. Hospital treatment is based on giving patients intravenous fluids to stop dehydration and antibiotics to fight infections.

There are however several experimental vaccines and drug treatments for Ebola under development, but these have not yet been fully tested for safety or effectiveness.

The medical charity Medecins Sans Frontieres is to start clinical trials of some of these treatments in West Africa in December.

Blood transfusion

The foundation, run by former Microsoft boss Bill Gates and his wife Melinda, said that it would work with several private partners to develop convalescent plasma treatments.

The treatments would used blood donated from Ebola survivors who had been screened for diseases.

Speaking earlier this month, Bill Gates said more research into Ebola was needed

The liquid plasma from the blood, containing disease-fighting antibodies, would then be isolated and injected directly into patients.

The remaining blood could then be returned to the donor, allowing them to donate blood at a faster rate than before.

Dr. Papa Salif Sow, an infectious diseases expert working with the foundation, said that the programme would work with governments to "to rapidly identify and scale up potential lifesaving treatments".

"The Gates Foundation is focusing its R&D investments on treatments, diagnostics, and vaccines that we believe could be quickly produced and delivered to those who need them if they demonstrate efficacy in stopping the disease," he said.