Post #718: Key graphs updated to 6/16/2020. Total of 11 new cases in Fairfax County today

This post updates some key graphs to 6/16/2020.  The sharp dropoff in new cases in Fairfax continues.  Whatever it is we’re doing, all I can say is, let’s keep doing it.

These numbers tend to fluctuate a bit from day to day, depending on how “backed up” the State reporting office is by 5 PM close of business on the prior day.  That said, today’s count of new cases in Fairfax is 11.  (No, I didn’t miss a zero — eleven cases.)

Maybe that’s an undercount, and we’ll see the rest of them show up tomorrow.  Maybe that’s real, and we won’t.  Either way, that’s low.  It suggests that any activity you’re doing now, in Fairfax, is pretty safe.  Based on the total number of adults in Fairfax, 11 cases represents a 0.001% daily chance of infection.

It’s hard to make any sense out of this.  In part, I think we’re finally seeing the seasonality of COVID-19 showing up in the Virginia data (Post #714).  But who knows?

  • Maybe we’ve just finally run out of uninfected people who are unwilling to wear a mask in public? So that we just had to burn through the non-compliant portion of the population?
  • Maybe we’ve infected enough of the at-risk workforce (e.g., healthcare workers, retail workers) that it’s slowing the spread that way.  So a key portion of the population has reached something like herd immunity?
  • Maybe the fraction of the population who can easily catch this is far smaller than the total?  And so all the easy targets have already been infected?
  • Maybe the well-educated population of Fairfax County has finally figured out how to do everything right?  Masks, distancing, and so on.

For sure, other than the Governor’s mandatory mask ordinance, it’s not like we’ve been doing hugely more to limit the spread.  And it’s far too soon to have reached “herd immunity” for the population as a whole.

My point is, if there is a reason for this slowdown in Fairfax, we’d surely like to pin it down, so that we could do whatever-it-is we’re doing in Fairfax, throughout Virginia.  But right now, it just is what it is.  There’s no apparent reason for it.

Anyway, outside of NoVA+, we’re getting to the point where any impact of Phase II re-opening should just start showing up in the data.  Phase II started about 11 days ago  outside of the NoVA+ areas.  And would begin to show in the red lines in the graphs below.  But, so far, nothing appears to be showing up.


Impact of re-opening, Phase I, in Virginia, update to 6/16/2020.  New case growth is slowing all across Virginia, but it slowed more rapidly in the “late” opening areas.  As a result, we’ve now reached the point where there are fewer new cases coming out of the “late” areas (NoVA, Richmond City, Accomack County) than out of the rest of the state.

That trend accelerated with the most recent case counts.  This is the plot of daily new cases.  As with the rest of this pandemic, I find it hard to think of any particular reason for what we’re now seeing.

It’s at the point where if Phase II re-opening has any impact, we should start to see it in the orange line below.  That started on 6/5/2020 in the early-re-opening areas, and it takes maybe 10 days for any uptick in cases to start to appear in the data.  Under Phase II, e.g., restaurants and gyms are open for limited indoor service, and the (legally allowed) size of indoor gatherings increases to 50.

Source:  Analysis of county-level data as reported by the Virginia Department of Health.  NoVA plus is Northern Virginia, Richmond City, and Accomack County.  The latter is in the late-reopening group because because they had 500+ cases of COVID-19 in two poultry processing plants.


Total cases, Vienna ZIP codes, update to 6/16/2020.  We continue to add an average of less than one case per day in 22180.


Daily new cases, Virginia and Fairfax County, last 28 days, update to 6/16/2020.  The dropoff in new cases that started at the end of May continued.   The seven-day moving average is now down to about 500 cases per day in Virginia, and 60 cases per day in Fairfax County.  As you can see from the graphs, that’s down from well over 1000 and about 300 per day, just two weeks ago.