How likely is it to develop flu-like symptoms from the flu vaccine?

Not likely: You can not get flu after getting fluvaccine and it is rarely people get serious side effect like guillen barre syndrome after getting flu vaccine 1 case per 100000flu vaccines given.

...: The flu vaccine is well tolerated by most people. It is effective in preventing illness along with good hand hygiene. The centers for disease control is a good reference site to learn more: http://www.Cdc.Gov/flu/protect/keyfacts.Htm http://www.Cdc.Gov/flu/protect/vaccine/index.Htm.