First, lets start with the indisputable facts: the seasonal flu vaccine causes Guillain-Barre Syndrome (GBS). Just read the package insert of any commercially available flu vaccine. The manufacturers and government health officials concede this fact. If you go to an emergency room with sudden onset of GBS symptoms, the first question the doctors will ask you is: Did you recently get the flu shot?
The only thing that is disputed is: how many people does it affect?