My MG was triggered by an extremely stressful period of my life. Thinking back before I was diagnosed the MG symptoms were there for years only in mild form as some occasional muscle weakness in my legs. It took the stress to trigger the general MG I have now. I think in most of us it is there it just needs a trigger to bring it out be it a vaccine or some other event to bring it out. Just my thought anyway. Now if I can just make it go away.
Al