A few years ago, my son had Guillain Barré Syndrome following a bout of 'flu. Guillain Barré is an auto-immune syndrome where anti-bodies are generated to combat, say, a 'flu, and end up attacking the body's own peripheral nervous system. Fortunately he was diagnosed and treated very quickly, and has completely recovered. I read that if someone has had Guillain Barré, they have about a 1% chance of getting it again in their lifetime.
My worry now is concerning Covid-19, particularly now that people seem to be ignoring the social distancing rules. Is is possible or likely that a Covid-19 infection could re-trigger his Guillain-Barré? He is in his 20's, and has just finished university, so he should be looking to start his career. But should he be shielding instead?