So I've had 4 shots total, most recent last fall (plus fu shot), all COVID were Pfizer.
In my 50s, am I eligible (or recommended) for a 5th shot?
You should get one bivalent booster if you haven't had it yet and it's been at least 2 months since your last COVID vaccination.
https://www.cdc.gov/coronavirus/2019-ncov/vaccines/stay-up-to-date.html
The bivalent was my 5th COVID shot.