I mean, we do have active research and treatment vectors involving this, but it's tricky for a few reasons.
One of the nasty ones is that accidentally teaching the immune system to attack the wrong thing is catastrophic, and we don't really have good general ways to undo learned response once present. (Exposure/desensitization therapy works for some things, but is still relatively early in its refinement.) Just look at the fun with the lone star tick and induced red meat allergies, and that's apparently a purely incidental outcome (e.g. it's not obviously a beneficial part of the tick's outcomes from biting things, just a quirk of primate biology not possessing a protein that every other mammal does, and getting upset when it finds it in the bloodstream).
Another example that comes to mind of when this doesn't "just work" is culturing uninfected immune cells from HIV+ patients, teaching them to kill HIV, and then putting them back.
AIUI, this works for a little while, but then it just shows back up again, like it never left. As it turns out, T cells happily share information between each other by making a happy little bridge between the two cells, and HIV is perfectly capable of spreading that way. Womp womp.
If you want to see a really strange immune outcome, go read the recent experiments about graft-versus-host disease potentially wiping out HIV in patients. (It didn't work for two patients in one experiment, so not extremely hopeful about the outcome, but it's a fascinating complex interaction. [1] [2]
One of the nasty ones is that accidentally teaching the immune system to attack the wrong thing is catastrophic, and we don't really have good general ways to undo learned response once present. (Exposure/desensitization therapy works for some things, but is still relatively early in its refinement.) Just look at the fun with the lone star tick and induced red meat allergies, and that's apparently a purely incidental outcome (e.g. it's not obviously a beneficial part of the tick's outcomes from biting things, just a quirk of primate biology not possessing a protein that every other mammal does, and getting upset when it finds it in the bloodstream).
Another example that comes to mind of when this doesn't "just work" is culturing uninfected immune cells from HIV+ patients, teaching them to kill HIV, and then putting them back.
AIUI, this works for a little while, but then it just shows back up again, like it never left. As it turns out, T cells happily share information between each other by making a happy little bridge between the two cells, and HIV is perfectly capable of spreading that way. Womp womp.
If you want to see a really strange immune outcome, go read the recent experiments about graft-versus-host disease potentially wiping out HIV in patients. (It didn't work for two patients in one experiment, so not extremely hopeful about the outcome, but it's a fascinating complex interaction. [1] [2]
[1] - https://www.nature.com/news/hopes-of-hiv-cure-in-boston-pati...
[2] - https://www.newscientist.com/article/mg23431244-400-immune-w...