Flu Shot?

Mercedes
So my doctors recommend the flu shot. I haven't had one since I was very very little. Other than that my mom did research and then always turned them down. And I've been fine. I only got it one time. So I'm thinking about it and if like to know pros and cons. Because I feel like if its past through my son than he wouldn't get sick. But I've also hear that the shots don't  really work anymore.