Multiple sick days post vaccine is the exception, not the norm.
With a vaccine, at least people can plan ahead a bit. I was a bit ill for a day after my first dose so I factored that in when getting my second dose. Didn't want to leave any urgent pieces of work knowing there was a good chance it would fall on someone else's lap.
If one catches COVID, it's more likely to stop them from meeting their responsibilities for longer than a day or two. The preferred choice seems clear.
Besides, sick days happen. If missing work causes a crisis, that's a failure to plan.