@kevintran - Even if the vaccine doesn't make us very sick our immune reactions can go "behind our backs". Perhaps your immune system put some strain on your lungs that haven't quite healed as yet? Or maybe something else has changed. The lungs are made up of different types of cells that help maintain homeostasis (the tendency toward a relatively stable equilibrium between interdependent elements, especially as maintained by physiological processes.). After an injury takes place, in order for homeostasis to be maintained the lungs can change the function of cells. Even though I have a lot of experience with my own lung cancer it is very very difficult to understand the lungs' cellular complexities and why more reparations do not take place.

There is a psychological component involved with SOB. How could there not be? I mean, all of our lives we're walking, running, jumping, swimming, living, and you take it for granted that when you inhale and exhale you will continue to do so! Then you can't! Whether your symptoms are organic in origin, or psychogenic, it is "real." Your mental health plays a huge role in your physical health/symptoms.

I hope that your future tests will give you answers and that you will come back and share them.