siderea points out that you probably have >a href="
https://siderea.dreamwidth.org/1882720.html">"at least one underlying condition" for which the covid vaccine is (still) recommended by the US government, because most people do: the list includes being overweight, high blood pressure, depression, former smokers, and "physical inactivity." She speculates that the list may have been drafted to be as inclusive as possible, by someone who didn't have the authority to say "just give it to everyone."
The current official announcements, widely echoed, sounds as though most people can't get the vaccine, because the FDA is now being run by anti-vaxxers. That is almost certainly not an accident: if you think you can't have the vaccine, you won't ask for it.
Siderea also points out that even if you aren't on that list, a doctor can prescribe this, or almost any approved medication, to anyone they think it's appropriate for. In other contexts, this is what they mean by "off-label" use of a drug.
Note, however, that this may affect whether you have to pay for the vaccine yourself, rather than it being covered by insurance.
It has been pointed out elsewhere that you can always lie to them: nobody has a complete list of former smokers, for example.