I like the excerpt below, taken from the flu vaccine insert itself. Gives me enormous confidence in the vaccine. Oh, here's a link for those who ask for such things:
http://www.fda.gov/downloads/BiologicsBloodVaccines/Vaccines/ApprovedProducts/UCM220624.pdf
"6.2 Postmarketing Experience
Beyond those events reported above in the clinical trials for FLUARIX QUADRIVALENT or FLUARIX, the following adverse events have been spontaneously reported during postapproval use of FLUARIX (trivalent influenza vaccine). This list includes serious events or events which have causal connection to FLUARIX. Because these events are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to the vaccine.
Blood and Lymphatic System Disorders: Lymphadenopathy.
Cardiac Disorders: Tachycardia.
Ear and Labyrinth Disorders: Vertigo.
Eye Disorders: Conjunctivitis, eye irritation, eye pain, eye redness, eye swelling, eyelid swelling.
Gastrointestinal Disorders: Abdominal pain or discomfort, swelling of the mouth, throat, and/or tongue.
General Disorders and Administration Site Conditions: Asthenia, chest pain, feeling hot, injection site mass, injection site reaction, injection site warmth, body aches.
Immune System Disorders: Anaphylactic reaction including shock, anaphylactoid reaction, hypersensitivity, serum sickness.
Infections and Infestations: Injection site abscess, injection site cellulitis, pharyngitis, rhinitis, tonsillitis.
Nervous System Disorders: Convulsion, encephalomyelitis, facial palsy, facial paresis, Guillain-Barré syndrome, hypoesthesia, myelitis, neuritis, neuropathy, paresthesia, syncope.
Respiratory, Thoracic, and Mediastinal Disorders: Asthma, bronchospasm, dyspnea, respiratory distress, stridor.
Skin and Subcutaneous Tissue Disorders: Angioedema, erythema, erythema multiforme, facial swelling, pruritus, Stevens-Johnson syndrome, sweating, urticaria.
Vascular Disorders: Henoch-Schönlein purpura, vasculitis."