Anaphylactic reaction. Not to be administered intravascularly. Not to be used against all possible strains of flu virus. Thrombocytopenia or any coagulation disorder; anxiety- & stress-related reactions, syncope, hyperventilation. Avoid injury from faints. Insufficient Ab response in patients w/ endogenous or iatrogenic immunosuppression. Interference w/ serological testing. Childn <6 mth.