An antibody test for the novel coronavirus will soon be available

Editor's note: The Economist is making some of its most important coverage of the covid-19 pandemic freely available to readers of The Economist Today, our daily newsletter. To receive it, register here. For more coverage, see our coronavirus hub WHEN A NEWvirus invades the human body, the immune system leaps into action. First to the scene are antibody molecules of a type called immunoglobulinM(IgM). These bind with proteins on a virus's surface, disabling it and marking it for destruction by c...