[conspire] COVID-19 update deux

[Rick Moen]

I wrote:

> In short:  Wow, pretty well.  Statewide, number of infections are 
> heading down.  In the Bay Area, more so.
[...]

> Good news:  R-eff for the Delta variant is (recently) well under 1.0 in
> California, and better than that in the Bay Area.
> 
> Quoting https://calcat.covid19.ca.gov/ "Nowcast" modeling:
> 
> Where                 R-eff estimate
> -----                 --------------
> California statewide  0.9
> San Mateo Co.         0.88
> San Francisco Co.     0.8
> Santa Clara Co.       0.97
> Alameda Co.           0.87
> Contra Costa Co.      0.87
> Marin Co.             0.92
> Solano Co.            0.94
> Napa Co.              0.99
> Sonoma Co.            0.85

I swear I was really careful in transcribing that data yesterday, but
FWIW it's less rosy today.

Where                 R-eff estimate
-----                 --------------
California statewide  0.9
San Mateo Co.         0.99
San Francisco Co.     0.89
Santa Clara Co.       1.03
Alameda Co.           0.94
Contra Costa Co.      0.99
Marin Co.             0.86
Solano Co.            0.86
Napa Co.              0.94
Sonoma Co.            1.01

So, maybe it's best revised from "very encouraging" to "slightly
encouraging on balance, but we need a higher vaccination rate, stat".

These are only composites of data models, anyway, and small number
differences probably don't mean much, as it's not that accurate.
The real metrics that matter are hospitalisations and ICU occupancy.

But the overall picture _statewide_ is a little more reliable and
stable, showing the Delta-driven infection wave tapering off (but not
there yet).


About general Delta characteristics, CDC has a rundown page, somewhat
dummied down for the lay reader:
https://www.cdc.gov/coronavirus/2019-ncov/variants/delta-variant.html

Summary points:

1.  Delta-driven wave was seen starting around June and elevated by late
July.  

2.  CDC promises more-detailed data about Delta's increased
infectiousness and transmissibility, including in some vaccinated
individuals, soon.  

3.  Breakthrough infections (of the vaccinated) are happening but _far_
less often than among the unvaxed.  Whether the vaxed, if
asymptomatically infected, can transmit the virus and how strongly is
under study.

4.  Vaxed people who get breakthrough infections spread the virus for a
far shorter time than do the unvaxed, and the former's viral load
probably goes down much faster.

As always, CDC leans towards being cautious and vague in its
public-facing announcements.



> For obvious reasons, this is key, and is our likely way out.  At
> https://www.smchealth.org/data-dashboard/vaccination-totals-locations-data
> , the county trumpets the percentage of _eligible_ county residents
> who've completed vaccination -- being target-focussed -- but that not
> what matters, but rather the percent of _everyone_ (including people
> under age 12 who aren't eligible), who've gotten vaxxed.  For that, we
> have to calculate.  Page says the county population is 774,990, and that
> 554,461 of us have completed a vaccination series.  That's 71.5%.

Today, 556,351 fully vaxed residents, equaling 71.8% vaxed.  Keep going,
people!  We need about 94%, so we can return to normal life.  We
routinely achieve 95% coverage of MMR vaccine (measles, mumps, and
rubella), so we can do that for COVID-19, too.