Flu question for board docs and medical pros

The flu is rolling through my kids small catholic school. There have been 5 or more kids with confirmed diagnosis and many others with same symptoms who haven't gone to the doctor.

My 13 yr old son started feeling sick on Saturday with a sore throat and very fatigued. Ran a temp of 102.

Sunday night my 12 year old daughter started feeling a sore throat. No fever.

Yesterday the both of them were running a fever of 102 plus even with round the clock tylenol.

My wife went down last night with the same thing. Fever. Body ache in the joints. Chills.

So far nobody has gone to the doctor.

My question is two fold:

1) For the first time in probably 20 years I haven't gotten the flu shot. I read that it takes two weeks to become effective. I considered running out to get it today, but worried that it might make me more susceptible to getting sick for the short period I usually feel like crap after I get it.

2) Antivirals: My 10 year old daughter and I have no symptoms yet, but I feel like it is a matter of time. Is there any way to get antivirals without a legit flu diagnosis in the house? Would it be worth the effort?

Any advice would be helpful.