It was indeed quite an accomplishment.
What was unexpected and ironic is what came afterwards, where opponents of the administration quickly got vaccinated in large numbers and supporters of the administration did not. There are some interesting graphs here [1].
Lately Trump was been pretty vocal about telling his supporters to get vaccinated, and even that doesn't seem to be changing many minds.
[1] https://www.npr.org/sections/health-shots/2021/12/05/1059828...