Last year, the US FDA issued an "Emergency Use Authorization" for Pfizer-BioNTech vaccine for Covid-19.
I read the wikipedia page on what that means, and it seems as though this can be issued under very lax conditions (e.g. human use after animal-only experiments). On the other hand, I know that the Pfizer-BioNTech vaccine passed "Phase III" trials.
What is missing, therefore, for the vaccine to qualify for "regular" FDA approval? Is it a longer period of time for evaluating the possibility of unexpected mid/long-term detrimental effects in vaccinated patients? Are there additional missing experiments/trials? Or perhaps just administrative procedures?
PS - I've gotten (both doses of) this vaccine already, so please don't mistake this question to about whether or not to get vaccinated.