Experimental drug for Ebola

An international team of scientists has successfully treated the Ebola virus in monkeys with the experimental drug ZMapp. The treatment resulted in recovery in 100% of the 18 rhesus macaques treated.

Three untreated monkeys died by day eight of the trial. However, those monkeys on ZMapp recovered, even with clinical symptoms such as liver dysfunction and haemorrhaging and when treated up to five days after infection.

Made by pharmaceuticals giant GlaxoSmithKline and the US government, ZMapp is a mixture of three antibodies that target Ebola virus glycoprotein. Binding of the antibodies blocks the ability of the virus to bind to cells, preventing the first step in the virus infection cycle. 

“All animals survived and had undetectable viral loads 21 days post-infection,” said Professor David Evans, Professor of Virology at the University of Warwick, when commenting on the work. “This is an extremely encouraging result for a virus which has an incubation period of 2-21 days in humans and for which no vaccine exists.

“[The researchers also] demonstrate that the antibodies are reactive - at least in the assays used - with the Guinean isolate of Ebola currently circulating in west Africa. This is an important confirmatory result since the antibodies were generated against the related Zairerian isolate of the virus.”

The first human trials of the potential vaccine are expected to start soon.

The Ebola epidemic has killed more than 1500 people in west Africa and the virus was recently reported to have spread to a fifth African country, Senegal. The World Health Organization said the disease could eventually infect up to 20,000 people. 

The results have been published in Nature.