> I think (from my parents and in-laws) that immunosuppression is normally associated with current cancer treatment.
There are other reasons a person would be considered immunosuppressed, and plenty of non-chemotherapy drugs that have immunosuppressive effects. But yes, cancer is one of them.
It would make no sense to include immunosuppressed people in the initial trials for a vaccine, the purpose of which is to determine whether a vaccine can induce an immune response.
> My selfish concern is then whether or not the vaccine will work for them.
We won't have hard data on that specific question for a very long time, but it's something your/their doctor would be better equipped to make an educated guess about, given the specifics of their situation ("immunosuppressed" can mean a range of things). In some cases, a vaccine might do nothing. In some, it might be actively dangerous. In some, it might have a weaker but still nonzero protective effect. But I wouldn't trust anything you read on HN that tries tell you anything more specific than that.
Unfortunately, vaccines can't really help immunocompromised people, as their immune system is simply unable to fight off any infection, regardless of whether it recognizes the infection or not (of course, this may be a matter of degrees). That is why, for example, people with advanced AIDS can die from essentially any pathogen.
Your answer isn't exactly wrong, but it's painting with a broad brush. "immunocompromised" is a broad term (even more so than "immunosuppressed"), so there definitely are people who are immunocompromised who could potentially benefit from a vaccine (again, we don't have hard data on that yet for any of the vaccine candidates and won't for a while).
They do help indirectly - by innoculating the 90% who can take a vaccine, the 10% who can't (for example babies when it comes to measles vaccines) are unlikely to actually catch the disease.
Oh, for sure, I wasn't trying to say vaccines shouldn't be used! They are extremely important to a healthy population overall, and it is all the more important for people with healthy immune systems to get them to help protect those that can't benefit directly.
Transplant recipients (which must be on suppressants for life) can and do take vaccines and they work. They generally can't take live virus vaccines, but that's about it AFAIK.
There are other reasons a person would be considered immunosuppressed, and plenty of non-chemotherapy drugs that have immunosuppressive effects. But yes, cancer is one of them.
It would make no sense to include immunosuppressed people in the initial trials for a vaccine, the purpose of which is to determine whether a vaccine can induce an immune response.