>. Especially as someone who recently had both Flu A then Flu B.
I had flu A one month ago and my daughter had flu B recently (she's had the nose vaccine and had a very mild symptoms). My daughter infected my wife, who also got flu B but I did not get it at all.
It's the same with almost every kind of infection so far (except covid, but even with covid we all got very different symptoms) -- and I'm grateful for it, because all of us being sick at the same time would make it much worse overall.
I read that we are attracted to people who have different imune systems than our own.