www.telegraph.co.uk/global-health/science-and-disease/previous-waves-have-relatively-small-modellers-worried-indian/
" the answer comes down to simple, if counterintuitive, maths. Professor Adam Kucharski, one of the Sage modellers from the London School of Hygiene and Tropical medicine, explains it like this: “The issue is that many people have a mental image that we’ve [already] had the biggest possible epidemic waves, whereas we’ve actually had ones that are relatively small compared to what could have happened without control measures in place.
“Because of these controls, only a fraction of the people who could have got infected in the past year or so have been infected, so they’re still out there.
“Of course, for many of these people vaccines have now decreased their risk substantially. But a very large number of infections that come with a very small individual level of risk can produce a similar outcome to a smaller epidemic that carries a larger individual level of risk”.
And this is exactly what the Sage modelling shows"