To vacinate you first need a proper vacin, it takes month to develop and produce a vacin. If a manufacture doesn't predict the up coming kind of flu properly, the vacins will be useless.

When you have a drill, it's not handy to have normal people, going there to do a normal thing (getting there flu shots), because it will lack any realistic behavior. There are volenteer clubs, that supply people at drills which are instructed to behave in a certain fashion.

Secondly released press has always been more positive than the people envolved think. I have been volenteers for many drills and generally there where many many "learning points", even though the press where positive about it.