It was clear quite early on that Covid was largely a disease of institutions. Care home residents comprised c50% of all deaths, despite making up a fraction of the population, and hospital infections have been the major driver of transmission rates. Citadel protection was vital.
Correct for 1 year ago, unfortunately that info is not correct anymore, the rate of those in ICU during delta is up to 25% under 40s. I know personally 3 families in the US that have had their under 5 year old in ICU for up to a week, not just for observation. Severe nausea, vomiting and diarrhea, they have to be sedated and put on fluids as they refuse to eat, drink or even talk, that is how covid affects them. These were completely healthy active toddlers. BTW something not mentioned here is that Delta does have different symptoms to Alpha strain.