flu shots and the flu

My nephew (almost 2yo) had a flu shot Monday. He spent some time in my house this weekend, and now everyone in the house is spewing fluid from both ends. Is it possible that we caught the flu from him, or is this just a coincidence?
I work retail, and the other’s in the house work for the school district, so it’s not like we’re isolated, but to all get sick simultaneously would suggest a common source.

I was under the impression that the “new” shots didn’t make you sick.

I’m not seeking medical advice, just have a thirst for knowledge, and want to know whom to blame:)