Well, m'dear, I'll tell you the truth:
When you get the shot, it's so much better than the nasal spray. The antibodies are already in your blood; when it goes through your nasal passages, it spreads Q U I C K E R. It goes straight to your lungs.
Nasal spray: BAD!
Though, the bad thing about the shots, they're scary as s**t, I cry every time.
Then again, your family could be like mine, and you could get majorly sick from something inside the actual shot (not the virus itself, something else), and make your body immune to the shot. That's what happened to my cousin; she didn't die from the flu, she almost died from the shot itself.
The best way to do this thing, in my opinion: Don't get the shot, even if your mother says so. You could get majorly sick and die. Just remember to wash your hands and don't come into very close contact with school cafeteria food. Make your own lunch, and stay AWAY from the nurses office/sick kids.
^^ Hope that helped.