But according to CDC, both people have to be vaccinated to talk to each other inside. This means that if one person is vaccinated you can't see you're immuno-compromised grandparent anyway.
I see elsewhere you're claiming that long Covid isn't a thing. It is, full stop. Unless you're suggesting that living with lung and heart damage caused by Covid isn't a complication of Covid?
https://www.sciencedaily.com/releases/2009/07/090717150302.h...
https://erj.ersjournals.com/content/45/5/1463
https://www.sciencedaily.com/releases/2000/03/000329090639.h...
https://www.cdc.gov/flu/highrisk/heartdisease.htm#:~:text=St....
https://www.ncbi.nlm.nih.gov/books/NBK8142/
https://www.sciencedirect.com/science/article/pii/S0945053X1...