Researchers in Britain are preparing to infect healthy young volunteers with the virus that causes COVID-19. The aim is to speed up development of a vaccine that could help end the worldwide pandemic. This kind of research is known as a human challenge study. It is not used often because some people consider it morally wrong to infect healthy individuals for medical tests. But researchers say the risk is worth it, such studies can quickly identify the most effective vaccines. Peter Openshaw is one of the investigators leading the research. He said the studies are “enormously informative about a disease, even one so well studied as COVID-19.” Human challenge studies have been used to develop vaccines for diseases including typhoid, cholera, and malaria. The study will involve volunteers between the ages of 18 and 30.