Relevant story:

I worked in a pharmacy during COVID. Once vaccine supply balanced out to the point we could take walk-ins, we were told by corporate that even if someone was walking in without an appointment, we were to go into the system and make them an appointment for the current date and time. To clarify, this is a separate system than what bills insurance, notifies doctors, documents the vaccine etc. It's just an appointment system.

Dumb rule. Stupid. Did not follow it for weeks because we were busy, y'know, administering vaccines and dispensing medications.

Until I found out why we were supposed to do it...

This was the vaccine that you got one dose of, then a follow up dose ~6 weeks later. When you book an appointment, it automatically schedules the followup appointment and notifies the patient when it's coming up, helping us not get slammed with walk-in appointments and the patient not forget their second dose.

From that point on, I was adamant that appointments be made for every vaccine with multiple doses.