When I was a child I remember going to food banks. I remember the food bank having no eligibility checks whatsoever.
I also remember a few rich people going there just to take advantage of it, and I remember days where we were so far back in line that we got nothing while the rich people walked out happily.
That vaccination site isn't any different. Those vaccines were intended for poor, underdocumented, at risk populations. Your vaccination saved one life (yours), but cost many more. It's not any different from the days I went hungry due to egoists like you.
Nowadays, I'm obviously in a different situation, but I still can't stand people with this "fuck you, got mine" mindset.