I hadn't even thought about that, but I actually asked for and got a tetanus shot when seen at the beginning of March. It never occurred to me that could have been what took me out. I already had a severe sinus infection and maybe that was enough to knock my immune system down enough, but probably by adding the tetanus it pushed it over the edge!
Is it safe to get flu shots in the fall then? Or at least if other infections are under control?