Coronavirus cases are mounting but deaths remain stable. Why?

Something rather odd is happening in the two Europeans nations worst hit by Covid-19. The UK and Italy have a rising number of cases but a stable and very low number of deaths, even weeks after the cases started rising again.

At the time of writing, the UK records 1750 new cases daily and one death in a population of 67 million. With a roughly similar population and an average of 602 cases a day, Italy has had just over four deaths a day over the last month. The ratio of cases to deaths is nowhere near what it was at the height of the pandemic. The other notable feature is a shift of cases to a younger population. There can be several explanations for this trend. First, the viral agent may have mutated to a less virulent form. Although there are some published studies showing minor mutations, these are what you would expect from an RNA virus which is inherently unstable (think of the influenza viruses, which perpetually change their suits).