What went wrong with NACI? I have a theory, hear me out:

NACI confused relative risk with absolute risk, a rookie mistake, IMHO.

Side effect risk is higher for AZ than Pfz. That's what NACI was saying, and they're technically right about that.

BUT! ... 1/~6

If the risk of a serious side effect is .001% for AZ (1 in 100,000) and say, 0.0002% (1 in 500,000) Pfz, we could say that the relative risk is FIVE TIMES as high for AZ, and therefore Pfz is preferred. That's what NACI said, more or less.

BUT! ... 2/~6

But that's not a competent interpretation. A competent interpretation is that risk is very low for BOTH, and EITHER is much much less risky than contracting COVID, which is easy to demonstrate.

3/~6

NACI, please note that HERE relative risk is an important way to communicate meaningfully with the public:

4/~6

3% of Ontarians have contracted COVID, and .05% of the population (one in 2000 people) has died from it.

Your risk of dying from COVID in Ontario is .05/.001 = FIFTY TIMES HIGHER than your risk of a serious side effect from AZ.

5/~6

It's just not competent to say what NACI said. The relative risk is higher for AZ, but the absolute risk is miniscule compared to the risk of COVID.

NACI, step up and walk this back. You have done dreadful damage. No need to cite me, just fix this.

6/6