Post #1282: William and Mary weekly update

Posted on October 8, 2021

The Fall 2021 COVID-19 outbreak continues to wind down.

This table, with one line per week, corrects a small math error I made in the prior version, with one line per day. 


Why isn’t it zero?

FWIW, it’s something of a surprise to me that the virus continues to circulate at all at William and Mary.

At this point, the pandemic is largely a pandemic of the un-vaccinated.  Here’s the latest week’s numbers from Virginia.

Source:  Calculated from Virginia Department of Health COVID-19 dashboard.

These bounce around a bit from week to week, but the pie chart of new Virginia COVID-19 cases by vaccination status always looks about like this:

Source:  Calculated from Virginia Department of Health COVID-19 dashboard.

Given that the student body is 98% (?) vaccinated now, you more or less drop out the gray and orange segments of the pie, so to speak, when talking about William and Mary students.

Even if a modest portion of the vaccines were the less-effective J and J/Jansen vaccines, no matter how I figure it, 98% vaccination plus mandatory COVID-19 hygiene rules should put the student body well over “herd immunity”.  That combination should interrupt enough chains of transmission to bring the new case number right down to zero.

Possibly there’s leakage of new cases via contact with the rest of the world.  Possibly it just takes this long for an active epidemic of cases to die down.  (Although, with about 4.5 days for the typical “generation” of cases, it really ought to fall pretty fast.)  Possibly some of these are false positive PCR tests (unlikely when they are only doing testing-for-cause, I think).

In any case, at the moment, this isn’t too interesting from the standpoint of risk to individual students.   That’s good.  The low rate, coupled with the W&M administration’s characterization of most cases as asymptomatic or mild, suggests relatively low risk.

It’s still a bit interesting from the when-the-heck-will-this-finally-be-over standpoint.  I keep waiting to see any one place in the U.S.A. that appears to be free of COVID-19.  I occasionally scan all 3300 U.S. counties, looking for ones that appear to have no COVID-19 circulating.  So far, no dice.

But if ever there were a community that has everything in place to be over this, it has to be William and Mary.  With 98% vaccination rate and strict COVID-19 hygiene, if zero doesn’t happen here, it’s hard to see it happening anywhere.