Thanks! This is timely for me.

I've been puzzling over MHCs as it appears one of the MHC1 variants ( B*15:01) makes CD8 T-cells more effective at recognizing the covid-19 epitope 'WTAGAAAYY' and so making carriers of that MHC1 less susceptible to Covid-19 (and probably more likely to have asymptomatic infection?)

On top of that, I'm aware of CD8 going down as we age, and I have to wonder how much that has to do with the likelihood of serious disease going up with age(?)