Ok but you forget the most important think, flu can kill a pregnant woman....I am sure if the level of mercury was terribly high to cause problems health professionals will never recommend it for pregnant women.
As everything in medicine it's a balance of risks, and the risk is too much when you don't have the vaccin. I am a doctor, I didn't even blink on my gynecologist that reminded me the flu jab ...
But yep it's a choice. Same discussion I have all day with my patients . I hear all day but that anti hypertensive medicine has side effects. Yes true but the side effect of hypertension is stroke and paralysis or death. Your choice really, just make a well informed one.