Vaccine passports looks quite likely to come in many parts of the world, if they haven't already in your region, and there should be the option for a line in it saying "The rightful holder of this document cannot be vaccinated for medical reasons. This individual is to be treated equally to and granted all the same rights as a double-vaccinated individual."
They might ask you to testify and produce medical records, which shouldn't be a problem, and most likely might even require you to undergo an independent medical assessment by a third-party. A nuissance for sure,, but people had to go get the vaccines too, so... and it shouldn't take long, and in your case, will most likely only be required once.