How do you come to the conclusion of IFR likely <.5%? I’ve seen it consistently reported as 0.5-1.5%.
I think the Diamond Princess is the perfect case study to use as an upper bound, since we conducted extensive testing and the population is heavily skewed towards the elderly (and therefore higher risk than general population).
See https://www.medrxiv.org/content/10.1101/2020.03.05.20031773v...
> Adjusting for delay from confirmation-to-death, we estimated case and infection fatality ratios (CFR, IFR) for COVID-19 on the Diamond Princess ship as 2.3% (0.75%-5.3%) and 1.2% (0.38-2.7%).
The key point being that the “confirmed cases” numbers are useless due to massive overcounting, so you need to instead rely on serology.