Ebola refuses to die. Affected West African countries have repeatedly stopped transmission of the virus, only for fresh outbreaks to appear, seemingly out of nowhere. At least seven of these outbreaks were triggered by the virus lingering silently in people who have recovered from Ebola. By tracking its evolution, researchers have now discovered how the virus does this: it totally shuts down (Science Advances, doi.org/bf42). RNA viruses like Ebola make mistakes as they replicate their genes. But samples studied after a 2015 outbreak showed no new mistakes compared with samples taken 10 months earlier. To slow its mutation rate to a standstill, the virus must effectively have stopped replicating -something that has never been seen in viruses like Ebola.
展开▼
