It is a heavily guarded secret within the medical establishment (especially within the corridors of the CDC) that the Cochrane Database Review, which is the gold standard within the evidence-based medical model for assessing the effectiveness of common medical interventions, does not lend unequivocal scientific support to the belief and/or propaganda that flu vaccines are safe and effective.
Some vaccines have been shown to be more harmful, even lethal, than the diseases they are used to "prevent." Recently, attenuated yellow fever vaccine was found to be 5 times more likely to harm, and 12 times more likely to kill, than the natural yellow fever infections that only rarely occur in the wild.
Flu vaccines, according to the best scientific evidence available today, will only work against 10% of the circulating viruses that cause the symptoms of seasonal epidemic influenza. So, do the theoretical benefits really outweigh the known harms?