For those who don't know, the flu shot only contains like the 3 most popular strands predicted for that season. You can still get the flu because there are other strands out there you don't protect yourself from.
Also,
http://online.wsj.com/article/SB1000142 ... 29846.html You'll like this one NAB. I lost the link to the actual study that said NBA teams that high five more often do better than those that do is less.
Also, you're much much much more likely to contract the flu indoors and the flu basically dies quickly in outdoor exposure in the air so I wouldn't be too concerned about soccer players high fiving. They're more likely getting it in the classroom touching than playing ball.