Don’t worry, this really isn’t about math that you have to do, so much as math you ought to have already been thinking about. There is no heavy lifting here, but you may have to be able to follow the reasoning.
COVID is on the up-tick again in the US; well, lots of
nations. But not every up-tick or ‘surge’ is like the others. Let’s just take a
US-centric view. The first surge (Wave) was COVID spreading in a generally
pristine population of available hosts but it was also much more geographically
limited; it wasn’t everyone yet. It’s growth just reflects a simple power
function, it increases as it increases. If this isn’t that familiar to you, perhaps
you remember a story about someone, the “hero”, being asking what reward they
wanted for accomplishing some task for an emperor/king/ruler. The savvy reward recipient
simply asked to receive an item [for example: a grain of rice, a penny, a small
plot of land, …] that doubles in number each successive year on the anniversary
of their accomplishment. It’s a highly under-valued reward if the hero lives to
long life. [You could have the reward double every month, week, or some set
number of days instead of yearly if you are not a patience ‘hero’.]
The second Wave came along and still had access to a wide-open
population where more people hadn’t been infected than had been. Plus, the
number of points from which a transmission can originate was vastly greater as
a result of the first Wave. It had carriers in every state. So, even though there
were people who had been exposed there were many more who were able to transmit
it to all the very many others who had
not been exposed. It’s just a numbers problem. Remember that “hero” story?
Consider the implications if there are a lot more heroes and each hero creates
more heroes; or in this case the heroes are the viruses and the reward is a
punishment and it doubles say every week.
During the second Wave steps were taken to contain COVID and
progress was made by states invoking policies for reducing spread by using social-distancing,
masks, lock-downs, and the disruption of the easy ways to transmit the virus.
It worked, the spread declined. Then summer arrived and we re-opened (or many
states did) and celebrated. And of course, another Wave, the third, was upon us
as the school year began. I think this Wave ought to have taught us a decent
lesson about “cause and effect” but that’s a physics lesson and we are focused
on just simple math here right now. The third Wave was the ‘mother of all’
surges. Clearly the opportunities for transmission were excellent. The most
likely reason is by this time COVID was everywhere and still most people had
not been infected. By this time, COVID and policies regarding it had become
political issue. There’s no rational reason for this but then what has reason
to do with politics. Two important things happened. We had an election and
vaccines became available
By February the terrible third Wave was rapidly abating,
vaccinations were increasing, and it looked like the nation was making
excellent progress. The effort to vaccinate the population “surged” (I couldn’t
help myself) but began to run out of steam. It seems there were a lot of people
who didn’t want to get vaccinated. Remember that ‘political’ thing! Still, the
incidents of infection continued to decline, but a new COVID variant (Delta)
showed up on the scene. By July the fourth Wave had been seeded and would grow;
and of course summer was underway and people wanted to get back to ‘normal’. I
am not sure that people knew what 'normal’ they were going to be getting back
to but there was still a large number of people remaining available to be
infected; and the Delta variant was more transmissible.
This is where we need to do that ‘little’ math I warned you
about. Something interesting started to happen during the fourth Wave or just
became much more salient with this Wave. As the vaccinated portion of the population
increased the availability of hosts shifted toward the remaining unvaccinated.
This is not to say that the vaccinated population didn’t have some individuals
who were still going to be infected. We are talking about a large population
where the COVID immunity efficacy spectrum will still have some hosts that are
exposed to the virus exhibit symptoms and get sick. Just as the unvaccinated
population has its own immunity efficacy spectrum. What the COVID new
infections data was beginning to show was the unvaccinated were 90% of those
infected. The unvaccinated are also more likely to be hospitalized (greater
than 95%), and to be the majority of deaths from COVID (greater than 92%).
This is all that has already happened. The math to understand that is simple.
Look at the relevant numbers. What is much more important is what would some
simple math tell us will happen?
If 71% of the population is vaccinated, then 29% isn’t. For
a population of 330M people that 234M vaccinated and 96M unvaccinated. Now more
and more people are getting vaccinated, I suspect because slowly the math is sinking
in. But there is still a really big part of the herd that is operating under
different math than the rest of the herd.
With 110K (average) new cases a day, this is 110,000 cased
divided by US population 330,000,000; or 33 people per 100K citizens in a
population. But If 90% are due to unvaccinated people than that is 99,000 from the
96M people who have freely chosen to remain unvaccinated. And thus only 11,000 people
from the 234M who are vaccinated. Using those numbers: 99,000/96M is 103 people
per 100K unvaccinated citizens; and 11,000/234M is 5 people per 100K vaccinated
citizens. That’s a 20-fold difference. If all else were to stay the same, then
20 times more people die from just choosing to not be vaccinated. This should
have some implications for the herd.
Remember that ‘political’ thing? If the choice to be vaccinated
or unvaccinated is determined or influenced by that ‘political’ factor, then
over time for every 1 person in the political group who vaccinates dies from
COVID there are 20 people in the other political group who die from COVID. I am
not sure, but shouldn’t this be a problem for one of our political parties? The
amount of a problem it could be for them will depend upon how long the pattern
plays out.
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