Ebola drugs
Drugs to treat Ebola have ranged from antibiotics to experimental drugs. Many treatments used in related infections have also been tried in some cases. Here, Avigan Tablets, also known as favipiravir, produced by Japan's Fujifilm are displayed in Tokyo.Getty

An experimental drug used to treat mice infected with dengue helped a critically ill Sierra Leone doctor recover from Ebola, suggests a study published in Lancet.

The study calls for clinical evaluation of the drug.

The doctor was airlifted in September and admitted to Frankfurt University Hospital at a stage when he was showing signs of vascular leakage and severe multi-organ failure.

He was given antibiotics and a three-day course of an experimental drug called FX06, shown to reduce vascular leakage and its complications in mice with dengue hemorrhagic shock.

A marked improvement in vascular and respiratory function was seen under the combined measures of intensive care and drug treatment.

He was discharged after a 30-day observation period when no Ebola virus genetic material was detected in his blood plasma.

The doctors note that the intensive care medicine helped support the patient till his body could start antibody production to fight the virus.

FX06 is a peptide that binds to the surface of endothelial cells (which form the inner cell layer of blood vessels), and is believed to have a role in stabilising the endothelium.

The search for an effective treatment against the deadly virus that has claimed over 7,000 lives has seen a couple of vaccines showing promise, but recently one of the trials was halted following side effects in participants.

Antibodies in vaccines target viral proteins to block the infection. But mutations by viruses mean that different proteins are exposed, making vaccines inefficient.

Treatment using drug targets as with related filoviruses like the Marburg virus seem to be more effective. Studies have also reported positive results in using a molecule that mimics a critical region of the virus as a potential target.

Experimental drugs from ZMapp and TKM-Ebola have been used on some patients who have recovered. But large-scale clinical testing of these will take time.