Have you been sneezing or wheezing, maybe feeling a bit tired? You might be reacting to ragweed pollen in the air and suffering from seasonal allergies. Or, maybe your symptoms are the beginning of a viral infection, even COVID.   As we head into fall, it can be a bit hard to tell. MPR News host Angela Davis talks with two doctors about respiratory health — what’s causing symptoms and how to address them. They talk about why this third week in September is known as “peak asthma week,” who should get the new COVID vaccine and how to diagnose and treat environmental allergies.