We’ve certainly made our share of mistakes publicly on this blahg over the years, and by and large, the category you can count on to flub things up would be the statistical stuff*.
Lo and behold, a kind-hearted BSer pointed out to us that no, our post yesterday claiming a 1 in 20 chance of getting covid after you’ve been vaccinated, is quack. (They didn’t actually say it that way. But yeah.)
If you’re in need of a primer on statistics and want to use calculations of infection rates and efficacy to do it, they’ve provided this useful lesson from the New York Times has a lesson, apparently aimed at high schoolers?, where they break down the math for you.
Err, for us.
Per the NYT, and unlike what the ‘Snark asserted yesterday, the 95% efficacy rate actually means that the vaccine reduces the risk of catching it by 95%. Not 100%; there’s still a risk. But as this astute BSer pointed out, it’s not a probability of infection.
We’ll take the liberty of quoting this BSer directly since they did a way better job than we will in attempting to explain it:
To illustrate, let’s say you live in a remote island of 10,000 people, 2,000 of whom would contract Covid (assuming a vaccination doesn’t exist). As a person on that island, your chance of being a part of the sick population is therefore 20%. But if you were to get the vaccine, it would reduce your risk of getting sick by 95%, so your chance of getting sick would drop from 20% to 1%. That’s what’s meant by “95% efficacy.”
They also made the point that it’s important to get this stuff right, and yes, ABSOLUTELY!!
If we still flubbed it here – or anywhere – we invite corrections!
Thank you to this BSer for taking the time to write in.
Or probably just anything mathy. We’re not SmartSnark, we’re just EssaySnark. The most recent stats class we took? Yeah, that was practically before you were born (no joke).
Tell us what you think.