[mysterio]

You are correct that the exact mechanism of GBS is still being studied and hasn't been outlined definitively.

When Guillain-Barré is preceded by a viral or bacterial infection, it is possible that the virus has changed the nature of cells in the nervous system so that the immune system treats them as foreign cells. It is also possible that the virus makes the immune system itself less discriminating about what cells it recognizes as its own, allowing some of the immune cells, such as certain kinds of lymphocytes and macrophages, to attack the myelin. Sensitized T lymphocytes cooperate with B lymphocytes to produce antibodies against components of the myelin sheath and may contribute to destruction of the myelin. Scientists are investigating these and other possibilities to find why the immune system goes awry in Guillain-Barré syndrome and other autoimmune diseases. The cause and course of Guillain-Barré syndrome is an active area of neurological investigation, incorporating the cooperative efforts of neurological scientists, immunologists, and virologists.

But the instances of occurrence in those who have had a flu vaccine is one case per million doses. Whether the flu shot is even causing that one case has yet to be "proven."

So, basically, when the anti-vaccine woo-woos run around spouting that the flu shot will probably give you GBS, they are incorrect.

[TigersEye]

So, basically, when the anti-vaccine woo-woos run around spouting that the flu shot will probably give you GBS, they are incorrect.

If they say it probably will they are definitely incorrect. If they say it possibly will they might be correct. Or not. No proof either way.

Congratulations! You have managed to lead this exchange miles away from the two questions I originally asked you. ;-)