Effectiveness of Influenza Vaccination Among General Practitioners

Study Overview
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Brief Summary
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Besides the personal protection, influenza vaccination especially needs to prevent transmission of influenza between GPs and their patients. The question remains if the vaccine is adding substantial benefit to the natural acquired immunity of GPs. Doubts are raised if an inactivated vaccine, which elicit especially humoral immune response, can give enough protection against virus replication and subclinical influenza infections. Until now no effectiveness studies of influenza vaccination were performed among GPs. This study will assess the effectiveness of an inactivated influenza vaccine in GPs against clinical respiratory tract infections and more particular against influenza cases with influenza positive nose and throat swabs (diagnosed by RT-PCR).

Detailed Description
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Two important aspects emerge when considering influenza vaccination of general practitioners as advocated by many guidelines. Besides the personal protection the vaccine especially needs to prevent transmission of influenza between GPs and their patients. In long-term elderly hospitals a possible benefit of influenza vaccination of the healthcare workers was noticed in reducing mortality among the elderly. But this specific situation is not fully transmissible to the general practice. GPs, having yearly close contact with several influenza cases, built up a high basic immunity and probably only suffer from minor symptoms. The question remains if the vaccine is adding substantial benefit to this natural acquired immunity. In addition doubts are raised in the literature if an inactivated vaccine, which elicit especially humoral immune response, can give enough protection against virus replication and subclinical influenza infections. Until now no effectiveness studies of influenza vaccination were performed among GPs. High time to look more closer to these issues. Comparisons: the effectiveness of an inactivated influenza vaccine compared with no vaccine in GPs against clinical respiratory tract infections and more particular against influenza cases with influenza positive nose and throat swabs (diagnosed by RT-PCR), besides serological defined influenza cases and taking important independent variables into account

Official Title
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Effectiveness of Influenza Vaccination (Alfarix)in Preventing Clinical Influenza Cases Among General Practitioners: Non-Randomized Clinical Trial.

Conditions
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Influenza

Intervention / Treatment
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* Biological: Alfarix


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria:general practitioner with an active practice in Flanders, Belgium - Exclusion Criteria:other specialists in medicine -

Ages Eligible for Study
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Minimum Age: 25 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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Design Details

Primary Purpose: Prevention
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Intervention/Treatment |
| --- |
|Biological: Alfarix|nan|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| number of respiratory tract infections |  |  | 
| number of influenza cases defined as a RTI with positive nose and throat swabs |  |  | 
| number of influenza cases defined as a RTI with 4-fold IgG titre rise |  |  | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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influenza vaccine, general practitioner