a clinical trial of an inactivated quadrivalent influenza vaccine in chinese children aged 3 to 8 years

Conditions: Influenza

Summary: routine annual influenza vaccination is recommended for all persons aged ≥6 months who do not have contraindications. for those aged 6 months through 8 years who have previously received ≥2 total doses of trivalent or quadrivalent influenza vaccine ≥4 weeks apart, they require only 1 dose of influenza vaccine. for those who have not previously received ≥2 doses of trivalent or quadrivalent influenza vaccine, they require 2 dose of influenza vaccine. but the evidence on how to select vaccine doses for quadrivalent influenza vaccine is limited in china. the study is a prospective, open-label comparison of the immunogenicity and reactogenicity of 1 versus 2 doses of an inactivated quadrivalent influenza vaccine in subjects of 3-8 years old with different history of influenza vaccination.

subjects receive 2 dosed of quadrivalent influenza vaccine 4 weeks apart. blood samples were obtained from children at 3 time points-before receipt of dose 1, 4 weeks after receipt of dose 1 and before dose 2, and 4 weeks after dose 2. hemagglutination inhibition (hai) antibody titers to the a/h3n2, a/h1n1, and b antigens included in the vaccine were measured at each time point

Eligibility criteria:
inclusion criteria: * aged 3-8 years old * healthy subjects judged from medical history and clinical examination * subjects themselves or their guardians able to understand and sign the informed consent * subjects themselves or their guardians can and will comply with the requirements of the protocol * subjects have received ≥2 doses of trivalent or quadrivalent infuenza vaccine before enrollment (doses need not have been received during same or consecutive seasons); subjects have not received infuenza vaccine before enrollment * subjects with temperature \<=37.0°c on axillary setting exclusion criteria: * subject who has a medical or family history of any of the following: allergic history, seizure, epilepsy, brain or mental disease * subject who is allergic to any ingredient of the vaccine * subject with damaged or low immune function which has already been known * subject with acute febrile illness or infectious disease * major congenital defects or serious chronic illness, including perinatal brain damage * thrombocytopenia, blood coagulation disorder or bleeding difficulties with intramuscular injection * subject who has serious allergic history * subject who developed guillain-barre syndrome post influenza vaccination * any prior administration of immunodepressant or corticosteroids in last 6 months * any prior administration of influenza vaccine in last 6 month * any prior administration of blood products in last 3 months * any prior administration of other research medicine/vaccine in last 30 days * any prior administration of any attenuated live vaccine in last 14 days * any prior administration of subunit or inactivated vaccines in last 7 days, such as pneumococcal vaccine * any medical, psychological, social or other condition judged by investigator, that may interfere subject's compliance with the protocol or signature on informed consent for subject's guardian

Keywords: safety, immunogenicity, quadrivalent influenza vaccine