Persistence of Immune Response After Vaccination With Influenza Vaccine

Study Overview
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Brief Summary
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This clinical study will be performed in subjects aged 12-60 years old enrolled in NCT01310374 who received 2010 seasonal influenza vaccine to evaluate the persistence of the immune response of influenza vaccine up to 24 months after vaccination.

Detailed Description
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Subjects were previously vaccinated at 12 to 60 years of age with 2010 seasonal influenza vaccine.The persistence phase starts 24 months after the primary vaccination and blood samples will be taken at 6, 12, 18 and 24 months after primary vaccination. Subjects whose antibody titer less than 1:40 at 6 months after primary vaccination will receive a booster dose of influenza vaccine.

Official Title
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Persistence Study of Immune Response After Vaccination With Influenza Vaccine in Healthy Population

Conditions
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Influenza, Human, Immunisation Reaction

Intervention / Treatment
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* Biological: seasonal influenza vaccine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: aged 12-60 years old male or non-pregnant female volunteers received 2010 seasonal influenza vaccine clinically healthy as determined by: medical history inquiring and physical examination provide written informed consents before joining the trial Exclusion Criteria: without history of 2010 seasonal influenza vaccine administration, allergic to any ingredient of vaccine, autoimmune disease or immunodeficiency, severe adverse reaction after vaccination, such as allergies, hives, breathing difficulties, angioedema or abdominal pain, severe acute and chronic diseases axillary temperature over 37.0℃ at the time of vaccination.

Ages Eligible for Study
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Minimum Age: 12 Years
Maximum Age: 60 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: vaccinated group<br>Vaccinated group means that subjects whose antibodies less than 1:40 6 months later after primary vaccination will receive a booster dose of seasonal influenza vaccine. | Biological: seasonal influenza vaccine<br>* subjects whose antibodies less than 1:40 6 months later after primary vaccination will receive a booster dose of seasonal influenza vaccine<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| change from serum antibodies against vaccine-related influenza virus at 6,12,18,24 months | Persistence of antibodies in all subjects with respect to components of the investigational vaccine - month 6，12，18，24 | 6，12，18，24 months after the primary vaccination | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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influenza vaccine, immune response, persistence