Seriously, Covid is extremely low on my list of worries if I am close to a nuclear explosion. Like so far down that I can't see why it should be mentioned at all.

Radiation, access to food/water and breakdown of society are the only realistic concerns I can think of right away.

And I am not really sure if preparing is all that helpful, at least not the kind of preparation that is mentioned here. What I need is a way of providing food long term (years), and be able to defend it. In a place without radiation.