The Homa Files

Or, would we morph to a “pandemic of the vaccinateds”?
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Biden keeps blaming (shaming?) the persistence of the coronavirus on the folks who “stubbornly” refuse to get vaccinated.

That raises the headlined question: “If we got to the point that 100% of the population was vaccinated, would the coronavirus finally be vanquished?

Let’s put aside politics, religion and even the debate on natural immunity … and just run some numbers.

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Starting Point

Early-on we were told that the vaccines were roughly 90% effective against symptomatic infections.

English translation: Comparing matched samples of fully vaccinated and unvaccinated study participants … roughly equivalent in their natural susceptibility and their viral exposure … 90% a fewer vaccinated people became symptomatically infected (as compared to the symptomatically infected unvaccinated participants).

Currently, the CDC is reporting that about 70% of the adult population (18 and over) has been vaccinated.

About 225 million Americans fall into the 18 and over category.

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Step 1

To illustrate the math, we’ll use the 70% and 225 million numbers.

There are about 67.5 unvaccinated adults (100% minus 70% = 30% times 225 million equals 67.5).

And, assuming full vaccine effectiveness (90%), there are 15.75 million vaccinated adults who are medically equivalent to the unvaccinated adults (225 times 70% times 10% equals 15.75).

Let’s coin the sum of those 2 groups UnVaccinated Equivalents or “UVEs”..

So, at full vaccine effectiveness (90%), we have 83.25 million UVEs  (67.5 + 17.5 equals 83.25) … that’s about 37% of the over 18 adult population.

But, the vaccines have waning effectiveness, right?

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Waning Effectiveness

It has been reported that, over the course of 6 months, the vaccines lose about half of their effectiveness.

Source

To keep the arithmetic simple, we’ll assume that 6 months after full vaccination, the vaccines wane to 50% effectiveness.

To start, let’s assume that everybody who is vaccinated got vaccinated exactly 6 months ago (and hasn’t gotten a booster shot).

That would raise the number of UVEs (unvaccinated equivalents) up to 146.25 million (equal to 65% of 18 and over adults)   … the 146.25 million is made up of 67.5 million unvaccinateds and 78.5 million vaccinateds whose vaccine effectiveness has waned (225 times 70% times 50%).

Let’s get more realistic…

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Base Case

The prior scenario assumed that all people were vaccinated exactly 6 months ago.

But, not all vaccinateds got vaccinated exactly 6 months ago … they got vaccinated over the course of 6 months … and, thus, theyare at varying stages of vaccine “wanedness” … somewhere between 90% full effectiveness and 50% waned effectiveness.

If we assume that the vaccinations were evenly spread over the 6 months (rather than all on day one) then the average vaccine effectiveness among those who have been vaccinated would be about 70% (the average — halfway between 90% and 50%).

That would give us 114.75 million UVEs (equal to about half of all adults)   … made up of 67.5 million unvaccinateds (225 times 30%) and 47.25 million vaccinateds with waned vaccine effectiveness (225 times 70% times 30%)

Let’s call that our base case.

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What if 100% vaccinated?

Now let’s bump the fully vaccinated rate up to 100% and see what happens…

There would be no unvaccinated adults, but there would be UVEs (unvaccinated equivalents) — the vaccinated adults with waned vaccine effectiveness.

How many of them?

Using the above logic and numbers, there would be 67.5 million UVEs (225 times 100% times 30%) … fully vaccinated adults whose vaccine effectiveness has waned … rendering them roughly equivalent to an unvaccinated person.

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Rscap

Note that the 67.5 million UVEs is — coincidentally, using the above assumptions — the same number as the number of unvaccinateds who are currently walking around.

And, it implicitly assumes that everybody gets a booster every 6 months … to keep resetting the effectiveness clock.

To be fair, this estimate doesn’t adjust for any accumulated effectiveness that comes with successive booster shots or pre-existing natural immunity).

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The bottom line

Based on these rough estimates, we won’t move above our current level of coronavirus exposure even if 100% of the population gets vaccinated.

So, Biden will eventually lose his talking point of a “pandemic of the unvaccinated” … and, unless there’s a marked improvement in the vaccines’ “durability”. we’ll morph to a “pandemic of the waned vaccinated”

That’s not a medical or philosophical point … It’s simple (?) arithmetic.

This entry was posted on December 9, 2021 at 7:30 am and is filed under COVID - vaccine, COVID-19 Tracking. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.