Evaluation of the Effectiveness of Vaccination With 2009 H1N1 Vaccines During Influenza Season 2010-11

Study Overview
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Brief Summary
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A cohort of 3000 adults is followed to evaluate the effectiveness of the monovalent 2009 H1N1 vaccines used 2009-2010 and seasonal influenza vaccines used 2010-2011 in preventing the first laboratory-confirmed 2009 H1N1 influenza during the influenza season 2010-11.

Detailed Description
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In the beginning of the study, changes in the background information collected in the original study (conducted 2009-2010) are asked with a questionnaire. Information on influenza vaccinations is collected with vaccination cards and monthly short message service (SMS), and verified in registers, if needed. If an epidemic caused by the 2009 H1N1 virus starts in Finland, the participants are asked to actively report symptoms of influenza like illnesses (ILI). The symptoms are also monitored by weekly SMS. In case of ILI, nasal and oral swabs are collected to verify the 2009 H1N1 influenza cases. Paired serum samples are collected at the acute on convalescence phase of the disease. The occurrence of laboratory-confirmed 2009 H1N1 influenza cases is compared between vaccinated and not (yet) vaccinated persons.

Official Title
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Evaluation of the Effectiveness of Vaccination With 2009 H1N1 Vaccines During Influenza Season 2010-11

Conditions
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Influenza Caused by the 2009 H1N1 Influenza Virus

Intervention / Treatment
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* Other: Follow-up
* Other: Follow-up


Participation Criteria
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Eligibility Criteria
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Inclusion criteria for the interview follow-up: Participating in the study Evaluation of a vaccination campaign with A(H1N1)v pandemic vaccines: a prospective cohort study (AH1N1-483-09THL) Assigned to use the services of Tampere health care centre; Written consent for the interview follow-up phase obtained by mail; Able to adhere to all protocol-required study procedures without any special burden or risk, as judged by the participant himself/herself Inclusion criteria for the confirmation of 2009 H1N1 influenza cases: Participating in the study interview follow-up of the current study 'Evaluation the effectiveness of vaccination with 2009 H1N1 vaccines during influenza season 2010-11 (H1N1-495-10THL) Assigned to use the services of Tampere health care centre Written informed consent for the confirmation phase obtained at the first study visit Able to adhere to all protocol required study procedures without any special burden or risk, as judged by the investigator or designate Exclusion criteria: No specific exclusion criteria will be applied

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 76 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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Vaccinated persons<br>The participants have taken one or more doses of 2009 H1N1 vaccine, either as a monovalent vaccine or as a part of a trivalent seasonal 2010-2011 influenza vaccine | Other: Follow-up<br>* Questionnaires, interviews, nasal/oral and serum samples, register data<br>|
| Not (yet) vaccinated persons<br>The participants do not want to take any 2009 H1N1 vaccine or have not received any yet | Other: Follow-up<br>* Questionnaires, interviews, nasal/oral and serum samples, register data<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To determine the effectiveness of 2009 H1N1 influenza vaccination in preventing the first episode of laboratory-confirmed influenza caused by the 2009 H1N1 virus during the season 2010-11 among vaccinated adults as compared to unvaccinated adults |  | September 2010 to April 2011 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To explore the ability of different vaccination regimens to prevent 2009 H1N1 influenza |  | September 2010 to April 2011 | 
| To explore the effectiveness of the 2009 H1N1 vaccines in subgroups stratified by age |  | September 2010 to April 2011 | 
| To evaluate the incidence, severity and possible complications of laboratory-confirmed infection with the 2009 H1N1 influenza virus |  | September 2010 to April 2011 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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2009 H1N1 influenza, vaccination, pandemic, effectiveness