Ugh, that sucks, sorry! Do you mean the actual flu, or a GI virus? We've had both fly through our house since the beginning of November, and no one has been well enough to even get the flu shot. DS had a cold that really hit him hard and ended up almost back inpatient. They caught it early, stopped his body from reacting, did MRI and lots of blood work and got his immune system under control. Now I'm sorting a wicked sinus infection and possible bronchitis, so ds can't really hang around me.
Ditto the suggestion of the syringe, it used to work for us.