Phase IV Clinical Trial of an Influenza Split Vaccine Anflu

Inclusion Criteria: * Healthy adults aged 18-60 years old * Be able to show legal identity card for the sake of recruitment Without vaccination history of seasonal split influenza vaccine in the recent 3 years * Not participate in any other clinical trials during the study * Not receive any immunosuppressive agents during and one month prior to the study * Be able to understand and sign the informed consent. Exclusion Criteria: * Woman： Who breast-feeding or planning to become pregnant during the study * Any history of allergic reactions; was allergic to any component of the vaccine, such as eggs or ovalbumin * Any history of severe adverse reactions to vaccines, such as anaphylaxis, hives, respiratory difficulty, angioedema, or abdominal pain * Autoimmune disease or immunodeficiency * Acute episode of chronic diseases or conditions, including chronic hepatitis, hypertension, diabetes mellitus and cardiovascular diseases * Guillain-Barre Syndrome * Women subjects with positive urinary pregnancy test * Any history of immunosuppressive medications or cytotoxic medications or inhaled corticosteroids within the past six months (with the exception of corticosteroid nasal spray for allergic rhinitis or topical corticosteroids for an acute uncomplicated dermatitis) * Axillary temperature \>37.0 centigrade at the time of dosing * Psychiatric condition that precludes compliance with the protocol; past or present psychoses; past or present bipolar disorder requiring therapy that has not been well controlled on medication for the past two years; disorder requiring lithium; or suicidal ideation occurring within five years prior to enrollment * Any medical, psychiatric, social condition, occupational reason or other responsibility that, in the judgment of the investigator, is a contraindication to protocol participation or impairs a volunteer's ability to give informed consent.