DeepSOIC wrote: ↑Wed Apr 22, 2020 1:54 pm

For example, let's consider Italy. It has about 60M people, and the peak per-day new cases rate was about 5k, now coming down to circa 2.5k [1], and as far as I heard in the news, their medical system is saturated. If we want the virus to sweep over the population, at 5k/day it will take 12k days, about 32 years. Yikes!

This calculation is wrong because not the whole population needs be infected before the plague disappears. If a certain percentage is immune then the virus has no chance to distribute further and it will disappear automatically.

When reading on Wikipedia about the reproduction number then it talks about two numbers: the basis reproduction number (R0) and the effective reproduction number (Re). The relation between them is:

Re = R0 * (100% - n%) where n is the percentage of the population that is immune.

The goal is that Re < 1, i.e.: R0 * (100% - n%) < 1

If R0=3.1 then n=68%, if R0=2.5 then n=60% or if R0=1.4 then n=29% of the population must be immune.

So following your calculation then in the worst case it will take about ~22 years and in the best case ~10 years. This of course isn't a real option either.

DeepSOIC wrote: ↑Wed Apr 22, 2020 2:46 pm

But if the capacity of the medical system is the constraining factor, the linear growth at rate that saturates the system is the fastest way to get everyone through the infection. Which is apparently about 5k per day...

I think the original intention of the "flatten- the-curve" strategy was to avoid to collapse the medical system but let the population go through the infection over a long time span.

However, from what I have read is that the probability to survive an artificial respiration is only 50%. I wonder if this applies to all ages or only the old or people with underlying health conditions.

Now, in the past it was said that only ~20% need medical help and ~25% of them, i.e. ~5% of all cases need artificial respiration.

So, this means still around 1.5 million (60000000 * 5% * 50%) in Italy could die due to/with corona.

That's why at least in Germany some experts say it must be avoided that people get even infected. Therefore the best anti-measurement is spatial distancing and additionally from next week on there is a duty in the whole country to wear a mask if you go shopping. The main strategy of these experts is to delay the pandemia to win enough time to find medicine or a vaccine against COVID-19.