Scientists from the WHO say the world could be at risk from a deadly disease. They do not know its name or what it does. They have called it 'Disease X'. It could come from a virus or micro-organism that scientists don't know about. Disease X could go unnoticed until it is too late, when it is spreading around the world. The WHO says the threat is serious. It is putting a lot of money into research. It is preparing a plan for an outbreak. It said: "Disease X represents the knowledge that a serious international epidemic could be caused by a [virus] currently unknown."
Disease X could come from various sources. It could come from existing diseases becoming strong enough against our vaccines; it could come from terrorism and bio-weapons; it could also come from DNA-changing technology that makes totally new viruses. The U.S. Centers for Disease Control and Prevention said: "Scientists estimate that more than 6 out of every 10 known infectious diseases in people are spread from animals." Today, people live closer together in cities. There is more international travel and tourism. These will make it easier for diseases to spread.