Every new disease
is different.
There's a slow
learning curve.
Is COVID-19 transmitted
mainly by breath, or
mainly by touching ?
We're not sure.
Why do so few
children get
infected, and
why do those
infected
children
often have
no symptoms ?
We don't know.
Are ventilators
helping or hurting ?
We're not sure.
Will there be
a second wave?
There have
already been
some small
second waves.
Countries that
did a lot of testing
from the start
fared much better
than countries
that did little
testing.
Consider Groningen,
in northern Holland:
The 2020
overall death rate
as of early May,
from all causes,
was up only 4%
from the prior year.
For North Brabant,
in southern Holland:
The overall
death rate
doubled.
The difference
may be due
to testing:
Groningen
refused to adopt
the national policy
of testing ONLY
severe and
priority cases.
They tested
as many people
as possible.
Britain did not ramp up
testing until mid-March , and
then limited testing to those
already in the hospital with
COVID-19 symptoms.
Of course testing
does not cure
the disease, but can
inform people they
are, or were, infected,
when they did not
know.
For early cases,
the disease was
probably spread
in hospitals
and doctors’
offices, where
there were
any elderly,
sick people.
The elderly
were more likely
to be going
to hospitals
or clinics for
other ailments,
at least until
mid-March.
Chinese authorities
quarantined those
who tested positive
in special facilities,
keeping them away
from the hospitals.
In Belgium,
all 210,000 people
in care homes,
both residents
and staff,
were tested in
the second half
of April -- about 10%
tested positive
for COVID-19.
The per capita
hospital admission
numbers for
different countries
in Europe all show
a dampening of the
growth that you
would expect from
the lockdowns.
A study of 391 cases
of COVID-19, and 1,286
of their contacts,
in the Shenzhen region
of China, found that
80% of cases were
transmitted by just 9%
of carriers, and that
only 11% of those
sharing a household
with a case,
caught the virus.
For the infamous
nursing home
in Washington state,
23 days after
the first case
was diagnosed, on
January, 20, 2020,
64% of residents
tested positive,
half showing
no symptoms.
It seems obvious
that prolonged
and close contact
with an infected
person transmits
the virus.
And the risk
is highest
in enclosed
environments,
such as households,
long-term care facilities
and public transport.
That's true of flu,
in general.
Ordinary flu strains hit
young people hard.
But not COVID-19.
And children do not seem
to transmit the virus much,
if at all, according to
pediatricians.
Children seem to have
ACE2 receptors,
the cellular lock that
the coronavirus picks,
in their noses,
but not their lungs.
Vitamin D protects
against colds and flu.
At the end of winter,
Vitamin D levels
are often deficient
in obese, dark-skinned
and elderly people,
groups that have been
more susceptible
to COVID-19.
17 years after the severe
acute respiratory syndrome
( SARS-1) outbreak,
and 7 years since the first
Middle East respiratory
syndrome ( MERS ) case,
there is still no vaccine
for either of those
coronavirus family
viruses !
How people react
to an easing of the
economic lockdown
is another mystery.
I expect to see
a lot of caution
from people
over 40 years
old.
After two months
of lockdown,
as of mid-May,
the U.S. probably
reached the point
where continuing
to hold back
the economy
is becoming
worse than
the disease.