Maybe you are on to something there with the immune response to an unknown virus. I had Covid and tbh, I had colds much worse than this virus. I didn’t even know I had Covid until I got tested because I thought I just had seasonal allergies! I’m not exaggerating on how light my symptoms were. I would rather have Covid than a cold because it was easier for me to manage those symptoms vs cold symptoms. With a cold I am stuck in bed feeling weak but with Covid I felt completely normal except a minor runny nose and head pressure along with shortness of breath. That’s all the symptoms I had which is why I thought I just had allergies. I have asthma and I’m recovering from a severe lung bacteria case I had a little more than a year ago so I’m surprised I handled it so well. I’m young so that might have something to do with it, but still it makes no sense because I thought immune compromised people were at higher risk which I am due to my asthma and recent lung infection. My lung branches are scarred from my infection as well so idk...Covid is weird.