I agree that finding properly stratified data that is comparing IFR and not just symptomatic CFR is quite tricky.
At a minimum though, if we assume the chart I linked is CFR and compare to the Covid 5-20% CFRs we've seen, we still get that order of magnitude difference for the very, very young. But like I said in my previous comment here, I don't think the statement for all under 30's holds. It'd have to be <18 years old (and to be clear while https://bmcmedicine.biomedcentral.com/track/pdf/10.1186/1741... is helpful, I still haven't proven anything)
I came across https://bmcmedicine.biomedcentral.com/articles/10.1186/1741-.... It's not clear if it's referring to CFR or IFR but I imagine it must be CFR given how high some of the numbers are (500 deaths per 1000 in some cases).
I agree that finding properly stratified data that is comparing IFR and not just symptomatic CFR is quite tricky.
At a minimum though, if we assume the chart I linked is CFR and compare to the Covid 5-20% CFRs we've seen, we still get that order of magnitude difference for the very, very young. But like I said in my previous comment here, I don't think the statement for all under 30's holds. It'd have to be <18 years old (and to be clear while https://bmcmedicine.biomedcentral.com/track/pdf/10.1186/1741... is helpful, I still haven't proven anything)