Dual culprits: Omicron and waning vax effectiveness …
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This headline from the AP caught my eye earlier in the week :
The story in a nutshell:
Facing rising infections and a new COVID-19 variant, colleges across the U.S. have once again been thwarted in seeking a move to normalcy.
They are starting to require booster shots, extend mask mandates, limit social gatherings and, in some cases, revert to online classes.
Cases in point:
Cornell University abruptly shut down all campus activities on Tuesday and moved final exams online after more than 700 students tested positive over three days.
Hours later, Princeton University moved its exams online and urged students to leave campus “at their earliest convenience” amid a rise in cases.
A day later, New York University canceled all non-academic events and encouraged professors to move finals online.
Moments after I read that, I got a blast alert email from Georgetown:
We are experiencing a notable and concerning increase in COVID-19 cases on our campuses this week.
Yesterday marked the largest one-day total for COVID-19 cases within our community.
Accordingly, we are taking several immediate steps to help protect the Georgetown University community.
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Here’s the ironic twist:
Cornell, Princeton and NYU all report student vaccination rates of more than 98%.
I assume that Georgetown has about the same, near total vaccination rate.
In fact, practically all colleges in the U.S. required that students get vaccinated before returning to campus in the Fall.
That’s a key point that we’ll get to later.
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Why it’s happening…
One reason for the surge is Omicron — a well publicized and highly infectious strain of the virus.
A second, less publicized, but mathematically logical cause of the surge in infections is the vaccines’ “waning effect”.
Awhile back, we worked through the math:
The post is worth re-reading in its entirely, but for those of you who want to just cut to the chase…
It has been reported that covid vaccines start with an effectiveness rate over 90% but, over the course of 6 months, the vaccines lose about half of their effectiveness.
Again, re-read the original post for an explanation of what 90% effectiveness really means,
The bottom line…
To keep the arithmetic simple, we’ll assume that all college students were vaccinated last August.
That puts the August “cohort group” 4 months along the waning curve … down to about 65% vaccine effectiveness.
That means that — at the 4 month mark — about 1/3 of the matriculating students are medically equivalent to being unvaccinated.
One more time, , re-read the original post for an explanation why this is logically and mathematically true.
So, BINGO.
When a highly transmissible strain of the virus hits a campus that is, practically speaking, 1/3 unvaccinated, you’re dealing with a surge in cases.
That’s not medical theory or political philosophy … it’s simple arithmetic.
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So, what are colleges doing?
Simple answer, dusting off the old mitigation playbook: cancelling social events and athletic venues, requiring social distancing (preferably outdoors), finishing the semester with online classes and tests.
What they’d like to do is have all students get booster shots ASAP.
That would reset the the “waning curve” back up to the full 90%+ effectiveness.
But, there’s a problem with that …
The official CDC policy is wait “at least 6 months after completing the patient’s primary COVID-19 vaccination series.”
That means, the cohort of students who got vaccinated in August won’t qualify for boosters until next February.
Uh-oh
The Homa Files 
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