Yes, I noticed this as well, there are always a condition weakening in different cases. But I think it will work with any flu as well, we just never concentrated before so much on it, I guess if we will look at the numbers we will see it as well.

BTW when I was still in Israel flu shot was getting very popular, and thanks for this flu shot many old people died because they got horrible flu after it that their body couldnt deal with.

You know what I think is even our bigger problem? All the antiseptical stuff, we get so sterile we are not capable of fighting normal any infection anymore...where the times when we were eating non clean apples from the tree as a kid?