Yeah, immune compromised people are... well compromised! We're all supposed to be getting the shot to protect them. The fact that this population exists is reason to GET THE SHOT.
This bears repeating, again and again. The whole concept of herd immunity revolves around having enough people who can be immunized (or with immunity secondary to having had a given infection) surrounding those who can't such that an infection that is not already "right there" can get there.
We see breakdowns in this for what were once more common illnesses that had been virtually eliminated in pockets where immunization rates against those illnesses have fallen. Measles being the best example. If everyone who can be immunized is immunized, they can't serve as vectors for infection. They're an actual major buffer zone between those who cannot be immunized and whoever "somewhere, out there" may be infected and in the infectious stage of the illness.
I can be around those with measles, mumps, rubella, smallpox (eradicated, though, so that's not gonna happen), chickenpox, hepatitus A and B, and a number of other things and not only have a very near zero, if not zero, possibility of infection myself, but the same for being able to carry and transmit to others.
Vaccines work in populations by "cutting off the oxygen to the fire" such that "the infection fire" has nothing to feed it. There are always those who cannot be vaccinated, and this effect protects them, too, because those surrounding them cannot become vectors.
This has always been the principle behind vaccines at the population level. And vaccines are not particularly effective at the population level unless enough of the population receives them. If only a small percentage of a given population gets immunized, that still leaves the majority as "the oxygen" for "the infection fire" which will, invariably, keep on raging (or will until enough people have died and enough others have survived the given vector such that population level herd immunity is reached - and what sane person proposes that as a moral or sensible option?).