they dont put chemicals in it so to speak, our bodies are made up of those self same chemicals really, its just an inert (dead) form of the virus basically to give your body a pattern to make antibodies.
i had mine and had no side effects and havent been sick since the first tri before i had the jab. your immune system is lowered while preg and what could be a normal cold can turn life threatening when your immunity is compromised. everyone should get the jab to protect their unborn baby. one of the girls who has just given birth lost her sister to swine flu last year and another lady lost her baby just after birth partly she thinks due to her having swine flu while preg. other ppl have said that catching the flu while preg contributed to brain damage in babies and other complications. all that can be prevented by taking a little injection.
i dont wanna be preachy and i totally understand that a lot of ppl dont take vaccinations anymore as they think its unneccessary but id urge everyone to seriously consider it and at least research the subject before deciding to risk not getting theirs.