DO you know what, justasking, you might be on to something there - I too have historically struggled with anything viral - I'm the last to catch something but when I do, I go down like a sack of potatoes, and stay down for much longer than anyone else. I ended up having a 5-year period of bed and housebound with CFS. It looked like it was never going to end, but I always felt it was immune-related.
However in 2014, I had a haematoma and a seroma after having my gallbladder out , and after all the vomiting and being flushed with IV antibiotics, I made a complete recovery - it was like my digestive system had been reset to 0.
But as we have between 2 and 4 DCs in the house at any one time, everything comes through the door, so usually over the course of the year, we'll get everything that is doing the rounds.
This winter, unusually, we've done quite well. Until about a month ago, when we all got this weird 'temp, bit of a sore throat, really nasty cough,' and we keep recovering, going back to school/work/uni, and then two days later it bounces back, flattening us all again. Just. weird. And completely fed up with it.