"You're important enough to have Secret Service protection, but..."

[John Dibble]

The flu very rarely kills you if you have access to medical care. Still, even if the president caught it he has access to the best care in the country, it's not like the flu is a real danger to him. If this was the bubonic plague or something, he should definitely get first dibs, but I don't think there needs be preferential treatment in this case. Ultimately I doubt a flu shot would be that important for the president.

The flu is rather bad this year though(my mom had it, woo boy, not fun), so get a shot if you are at risk. I won't be getting one, I never do, since I've got a tough immune system that handles stuff like the flu easily(if everyone in my house get's sick, I don't get sick).

[John Dibble]

You don't want to get the flu during the last weeks of your campaign

Indeed. They can pay for their own flu shots as far as I'm concerned though.