Two treatments for Ebola emerge from a clinical trial in Africa

NEWS ABOUT Ebola, a viral disease that kills up to 90% of those it infects, is usually grim. The latest outbreak, in the Democratic Republic of Congo (DRC), has thus far killed nearly 1,900 people and rages on. But on August 12th the grimness lifted somewhat with the announcement that two anti-Ebola treatments being tested in the country have proved effective. If administered when the first signs of infection appear, they boost survival rates to about 90%.

The treatments in question employ antibodies. These are special protein molecules made by the immune system in response to infection. They work by locking onto specific parts of invading pathogens, or of body cells infected by those pathogens—either gumming the target up and disabling it or marking it for destruction by other parts of the immune-system. It is possible, however, to give the immune system a helping hand by identifying suitable antibodies in advance, manufacturing them in bulk, and then injecting them into those infected by the target organism.

One of the successful treatments, code-named REGN-EB3, is a cocktail of three such antibodies, mixed by Regeneron, an American biotechnology firm. The other, mAb114, is a single antibody developed by America’s National Institute for Allergies and Infectious Diseases. REGN-EB3 and mAb114 were among four experimental treatments tested in a...