If you are familiar with all those studies (I’ve only seen a couple*), then there should be a downward trend in the IFR since May. Is there?
The IFR simply CAN’T be a fixed number while treatments are improving. That said, my 0.725% includes a lot of early cases, so, if it IS 0.65% presently, I’m pretty happy with my guesstimate.
*I’ve seen no study that gives me great confidence in the accuracy of the actual infection rate itself.
My real point, however, was unstated. I wanted to see if certain posters picked it up: Trying to achieve “herd immunity” via infections would be a very costly tactic.
IMO, your assessment of the coming vaccines is correct.
IFR numbers in April/May timeframe were estimated between 0.5% and 1%. By the end of May and into June, studies and CDC’s own numbers coalesced around 0.65% (0.64%-0.66%). By the end of June, I couldn’t find anything that suggested any IFR outside that range. I haven’t seen any updated numbers, but honestly I’ve been a little busy and haven’t kept up with newly published work as well as I had. It does appear we’ve improved our treatment protocols in the hospitals, finding new medications and other therapies to increase the odds of survival for those requiring medical assistance.
The original numbers for “herd immunity” are still valid. R0 of 2.5. Herd Immunity Threshold is 1-1/R0 or 60%. US population is 330 million, so 60% of that is 198 million. 0.65% of 198 million is ~1.3 million dead. That’s the absolute upper bound with the assumption made that survivors remain immune and that nothing changes with regards to vaccine availability, treatments, viral mutation, etc. I don’t think we’ll ever see anything close to that number because the treatments are improving, immunity does seem to hold for the overwhelming vast majority of the population, viral mutation has been extremely low thus far, and vaccines are just around the corner.