# 24-hr Quiz on the Safety Estimates of Vaccine Boosters

### Simple question - do you know the answer?

Here’s a simple mathematical exercise:

You have a medical product, say, Product X. It is supposed to prevent condition Y. Let’s say 10% of the population has a risk of bad outcome upon first exposure that makes it unlikely they will want the product in the future. Also, 0.1% of the population will have a serious adverse event that leads to hospitalization, and, of those 30% will die.

Clearly, on first exposure, your safety estimate would be 89.9% of the population can tolerate Product X.

That’s not too bad.

If the product is, say, a vaccine, and the delivery includes boosters, we need to estimate the population-level risk of double exposure.

Let’s assume of test population of 100,000 in your study:

**The Vaccinologist View**

**First exposure:** N=100,000

Drop-out or reported SAE: 10,100

Reported SAE rate (if unbiased): 10.1%

**Second exposure:** N=100,00-10,100 = 89,900

**24-HR QUIZ QUESTION:** What will the unbiased SAE population rate be for the booster in the second exposure?

What’s your estimate? Leave your answer in the comments.

The answer will be posted at 11:11 am tomorrow, 8/12/2022.

10.1%?

25%