[jstx1]

If I were you, I would look at efficacy and effectiveness of the vaccines. The effect on R0 is more difficult to estimate because you can't run a controlled study on it and you have a bunch of confounding factors.

[complexworld]

The person I'm talking with is young, healthy, and believes he is at very low risk of a serious case of COVID.

For society in general, the crux of his argument comes down to:

"Unvaccinated people are just as contagious as vaccinated, so why should I get vaccinated?"

I'm finding it surprisingly difficult to find unassailable evidence that vaccinated people are less likely to pass the virus on to someone else.

[jstx1]

> I'm finding it surprisingly difficult to find unassailable evidence that vaccinated people are less likely to pass the virus on to someone else.

Then search for the studies that look into this; my point is that they won't be using R0 as a measure.