I had full blown Covid in December, after having moderna vax + booster (2 shots each) + 2 sputnick vaxes
was badly sick with Covid for a week
by week 2, was back to normal
except for the fatigue
about a month ago, got 3rd booster of half dose moderna
very little side effects
in 2020, I was terrified of Covid,
not so much now...
but I still wouldn't want to have it in the winter in Moscow!!!
especially, if I was an inexperienced English speaking person with no local contacts
Older age often means a weaker immune system but can depend on the individual. Weed smoking also suppresses the immune system. For sure though COVID could hit many a person hard, I've only had two shots of Astra Zeneca and waiting for the Valneva vaccine (hopefully) to avoid the mRNA vaccines. I still firmly believe a decent mask that is as near as airtight as possible worn in public indoors locations can do a lot to avoid COVID and probably many other stuff, Flue etc. I also keep up on the hand held, mouthwash, etc with that in mind.
I think you're right Krim that being English speaking without much Russian is likely going to be a very unpleasant experience in a hospital in Moscow especially with the war backdrop. In any FSU hospital as you have pointed out it's not likely to be a good place to be. Crossing the border by train from Poland to Lviv a few years ago wasn't a fun experience as an English speaker knowing very little Russian but I was fortunate on that occasion to have a Ukrainian girl to translate for me in the carriage cabin to border guards.
At the moment though I think a lot comes down to weighing the risks of contracting COVID, trying to mitigate them and then considering if it's worth a stab at it. As 2tallbill rightly said I think that there can always be an excuse but you don't really get anything by playing safe all the time though that's not to say you might lose as by not playing safe it opens up more risk, that's life of course though. Sometimes I think you've just got to take as best an educated gamble and make a play for what you want. After all what's the point in living being sat around not going anywhere in life I figure.