Safety of H1N1 Influenza Vaccination in Pregnant Women

Inclusion Criteria: 1. Healthy pregnant women 2. Be able to show legal identity card for the sake of recruitment 3. Be able to understand and sign the informed consent Exclusion Criteria: 1. Cases, cured cases and close contact of influenza A (H1N1) virus 2. Subject that has a medical history of any of the following: allergic history, or allergic to any ingredient of vaccine, such as egg, egg protein, etc 3. Serious adverse reactions to vaccines such as anaphylaxis, hives, respiratory difficulty, angioedema, or abdominal pain 4. Autoimmune disease or immunodeficiency 5. Asthma that is unstable or required emergent care, hospitalization or intubation during the past two years or that required the use of oral or intravenous corticosteroids 6. Diabetes mellitus (type I or II), with the exception of gestational diabetes 7. History of thyroidectomy or thyroid disease that required medication within the past 12 months 8. Serious angioedema episodes within the previous 3 years or requiring medication in the previous two years 9. Bleeding disorder diagnosed by a doctor (e.g. factor deficiency, coagulopathy, or platelet disorder requiring special precautions) or significant bruising or bleeding difficulties with IM injections or blood draws 10. 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) 11. History of any blood products or seasonal influenza vaccine administration within 3 months before the dosing 12. Administration of any other investigational research agents within 30 days before the dosing 13. Administration of any live attenuated vaccine within 30 days before the dosing 14. Administration of subunit or inactivated vaccines, e.g., pneumococcal vaccine, or allergy treatment with antigen injections, within 14 days before the dosing 15. Axillary temperature \> 37.0 centigrade at the time of dosing 16. Psychiatric condition that precludes compliance with the protocol 17. 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