[chbot] Modelling virus spread...

[Volker Kuhlmann]

[Maybe the ventilators list is more appropriate???]


I believe your modelling may not be elaborate enough, and that any crude
home approach is not very meaningful. Are details of the modelling
method of those uni researchers available who advised the government?

Your model ending with an infection rate of 97-99% does not seem
plausible to me. Herd immunity should kick in before then. Numbers I
remember mentioned are 60-70% for sars-cov-2 although that's obviously a
guess, 80-90% for past commonly problematic diseases, and I remember
nothing above 95%. They might also have been vaccination rates, but
that's equivalent here.

It heavily depends on pathogen behaviour, effects, and how its disease
progresses. Some of those are still vague or unknown for sars-cov-2.
There are different results for different pathogens.


Yesterday in Germany someone compared covid19 deaths (positive test)
with life expectancy. The difference is 9-15 years (regional and
gender(!) differences). Then the numbers were corrected by the mortality
caused by pre-existing conditions (using data from a Glasgow study), and
the difference was still 8.5 years (women), 9.9 years (men). In other
words, men who die of covid19 lose 10 years of their life *after*
accounting for existing bad health. [1]

Saying only those who'd be dead next month anyway die of covid19 is
clearly not true.


The purpose of flattening the curve is not only to not overload the
health system, it is also to buy time for a chance of getting a
functional treatment, or the virus suddenly dying out (like SARS, but
it's not looking likely now), or any other unknown.

Whether the economic cost of trying to stop the spread is worth it
heavily depends on whether you're in the risk group, Siouxsie Wiles(?)
pointed out. And on how much value society puts on vulnerable people.

We could pick the best approach now, if we had the data from 6 months
ahead. I'm afraid large parts of the world are basically stuffed, like
Europe, America, Africa, and a few incompetent ones all over the place,
where things will normalise only once either herd immunity is reached or
an effective treatment becomes available, and there'll be many holes to
dig until then. New Zealand is one of the very few that have a zero
option.

The Swedish guy's recent comments (I can't find them now) about Sweden
and New Zealand are basically accurate. If no vaccine/treatment can be
found, both countries' approaches are best for their circumstances, but
New Zealand couldn't open borders for 10 years, if ever, for practically
no deaths, and Sweden avoided most of the economic impact. However we
don't know that "if" yet. Current restrictions buy us options. Billions
spent on research hopefully pay off.

Volker


[1]
https://www.tagesschau.de/investigativ/ndr/corona-lebenserwartung-101.html
It's not mutually exclusive with current death rates being up on previous
years
https://www.tagesschau.de/inland/uebersterblichkeit-deutschland-coronavirus-101.html
because they fluctuate lots, and the current increase is well within
previous maxima. Unlike other countries' fatality rates, Germany's have
not gone through the roof.

-- 
Volker Kuhlmann
http://volker.top.geek.nz/	Please do not CC list postings to me.