
The tricky math of Covid-19 herd immunity - Anon84
https://www.quantamagazine.org/the-tricky-math-of-covid-19-herd-immunity-20200630/
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learnstats2
I feel uninterested in R-nought (or R) when there is evidence for a huge
variance around how many people each person will infect.

Infections seem to happen at large gatherings: one person can be identified as
infecting 50 others simultaneously, especially in the early cases, even though
the R-nought is said to be no more than 2.5

That suggests infectiousness is an incredibly skewed distribution, to the
point of implausibility.

An epidemiologist apparently setting out R-nought as the underlying basis for
their modelling (or even: communicating it to the public as such) worries me.

I wouldn't begin any statistical modelling unless I was thinking about the
distribution of infectiousness more generally: even a high school student of
statistics would know to look beyond the mean and to the variance.

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dtech
Some people earn $0, others earn $1000000 a year. That doesn't mean mean an
aggregate like mean income isn't useful

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jessaustin
Income is a perfect example of a quantity for which mean is not an informative
statistic. Really, anything more-or-less bounded on one side is not well-
characterized by the mean.

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umvi
Well, one thing's for sure - the USA will reach herd immunity more quickly
than the rest of the world at the current rate.

The thing that bugs me about covid-19 is how we only try to optimize for
reducing deaths of that one thing (covid-19), while letting other types of
collateral damage resulting from said optimizations pile up unaccounted for as
side effects. Experts are clearly very bad at predicting second and third
order side effects resulting from covid-19 death reduction optimization.

To use a computer analogy, it's like going to extreme measures to refactor all
programs so that Covid19Exception kills as few processes as possible,
meanwhile processes left and right are dying at elevated rates due to
HeartExceptions and BrainExceptions (and in a few months CancerExceptions) and
the OOM Killer is on the prowl but nobody is noticing because they are
hyperfocused on Covid19Exceptions.

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rgbrenner
I think you've misunderstood what the experts are attempting to do. They're
not trying to get 0 covid deaths at the expense of all else.

COVID can easily overwhelm the hospital system all by itself. We saw that in
Italy and China... and hospital systems in several parts of the US are already
near capacity. Once they're overwhelmed, there will be no room left in the
hospitals, and they'll have to do one of two things: Start sending covid
patients home, which will increase the covid death rate and/or start refusing
patients with other injuries/diseases.. which will increase the deaths in
those cases.

The restrictions are all about preventing the hospitals from being
overwhelmed, and causing more people to die than currently. It just seems like
they're so focused on covid, because it spreads so rapidly that it can
overwhelm hospitals in a very short period of time.

Unfortunately with the numbers in Texas, Florida, and elsewhere... and with
how long it takes for restrictions to have an effect... it's very likely we'll
see what an overwhelmed hospital system looks like very soon.

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umvi
> COVID can easily overwhelm the hospital system all by itself.

1\. Is there anything a hospital can actually do to save someone with a
serious case of covid-19? As far as I know, ventilators are ineffective (and
may even make things worse?). If 100 people with _serious_ covid-19 are taking
up ICU beds, how many will live due to direct hospital intervention? If it's a
very low %, it seems like a no-brainer to turn away covid-19 cases in favor or
other, more treatable diseases. Otherwise it's like letting people with prion
disease use up all the ICU beds despite their condition being pretty much
untreatable.

2\. Anti-covid measures can do the inverse. Remember back in March/April/May
when all the hospitals in the USA were empty due to SIP? Most hospitals ended
up dismantling their temporary covid-19 field hospitals due to lack of use.

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lmilcin
If you look at statistics, death rates skyrocket in places and at the time
when hospitals are overwhelmed.

Also remember, doctors and nurses are people, too. Who is going to save your
ass if all staff is sick?

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umvi
If all the staff is sick, then 2 weeks later all the staff will be immune. So
just... Don't get sick during the window when all staff is simultaneously
sick.

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kayodelycaon
Is this taking into account possible reinfection and mutation rates? There's a
lot about the virus we don't know.

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SpicyLemonZest
The controversies over reinfection were about the idea of immunity passports,
which are much more sensitive to small errors - if 10% of people can get a
mild reinfection, that's a rounding error in herd immunity but a distastrous
gap in immunity passports. Epidemiologists are very confident that people who
recover from the virus get substantial and reasonably long-lasting immunity.

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fzeroracer
> Epidemiologists are very confident that people who recover from the virus
> get substantial and reasonably long-lasting immunity.

Citation?

