(CNN) Boo-Boo: How safe is it for vaccinated people to return to in-person work? An expert weighs in

However, the chance of actually contracting Covid-19 is greatly reduced if you’re vaccinated. According to Dr. Anthony Fauci, you have an estimated eight-fold reduction in risk of having coronavirus if you’re vaccinated compared to if you’re not – and an estimated 25-fold reduction in risk of having severe enough disease to cause hospitalization and death, which is truly remarkable.

This is a boo-boo. Fauci knows what he’s talking about; a statistician knows the true meaning of 8X risk reduction, but the statement is missing context for the typical reader.

Relative risk is not a simple number; it does not mean what it appears to. It is the expectation value of a random variable, which means it has value only in the context of a trial with some group, and the exposures of that group, as in,

“We did vaccine trials on a group, shot versus placebo, and this is the risk ratio for this group.”

You probably aren’t into math, so I’m going to make it real for you. Consider these types of groups of fully vaccinated people, in which there is initially one contagious Delta individual. Our sample has 10 Type A groups, 10 Type B groups, and 10 Type C groups.

• Type A: 8 college students jammed into a payphone booth.
• Type B: 8 employees doing phone sales out of a 10×10 room in a converted residence.
• Type C:  Skeleton crew of 8 in a large ventilated newsroom with forced air HEPA filtration.

The 8X risk reduction of Fauci, or the 2.5X – 5X  I previously computed in Delta Strain of COVID — We’re in for a Rough Ride; Napkin Calculation #3 are based on different groups. Provincetown tourists are a healthy bunch. Both numbers permit these results:

• Everybody in every one of the 10  Type A groups (payphone booth) get  Delta.
• 9 out of 10 Type B groups (small room)  get 6 or more Delta cases.
• 3 out of 10 Type C groups (newsroom) get 3 or more Delta cases.

This is completely compatible with an 8X risk reduction, because random variables do not follow ordinary arithmetic.

Are there  fatalities in A, B, or C? With extreme exposure, as in the payphone booth,  and Type B with the windows shut, it’s possible.

Is this anti-vaccine? No! You might even pick up a few new advocates. 14% of people have intelligence in the range of “bright.” The paradox exposed above makes bright people uncomfortable about something that doesn’t make sense. They are important  to the rest of us as trusted peers and guides.

In (CNN) Covid news coverage needs to start from this fact: ‘The vaccines work’, Brian Stelter is down on media fear-mongering and CDC messaging.  He states, almost true for the moment, that Delta is a disease of the unvaccinated.

That implies unjustified optimism. COVID-19 is not static. It has a huge tendency to mutate. There is already Delta+; virologists cannot set a limit.  We don’t yet know the consequence, in vaccinated individuals, of simultaneous infection with influenza and Delta.

Will vaccine uptake be maximized by hand-holding, with inaccurate, anodyne medical journalism? Something to think about.

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