Chances of senior cat catching COVID?

He's a 14 year old with CKD and HCM. He was stage 2 CKD as of last year, but at the tail end, so it's possible he's stage 3 now (though he's been stage 2 for 5ish years).

I tested positive for COVID this morning after waking up really sick. Our apartment isn't really big enough for me to quarantine myself, and he's unfortunately a velcro cat that will keep our landlords up all night screaming if we lock him out of the bedroom (or scratch up the door trying to get in).

Is it still a low risk for seniors/CKD+ cats, or is his risk significantly higher? And if he does catch it, are symptoms typically still mild in these cases? I've had it twice before, and he didn't catch it, but I'm still worried. There's not really much I can do to avoid him here without him being destructive and anxious.