Clinical trial NCT00221676: Effectiveness of Influenza Vaccination Among General Practitioners
Official title: Effectiveness of Influenza Vaccination (Alfarix)in Preventing Clinical Influenza Cases Among General Practitioners: Non-Randomized Clinical Trial.
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE4
Conditions: Influenza
Keywords: influenza vaccine
general practitioner
Lead sponsor: University Hospital, Antwerp
Sponsor class: OTHER
Collaborators: name: Universiteit Antwerpen
name: Eurogenerics NV
First posted: 2005-09-22
Enrollment: 300
Sex: ALL
Minimum age (years): 25
Maximum age (years): 76
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: NON_RANDOMIZED
Intervention model: PARALLEL
Primary purpose: PREVENTION

Brief summary: 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: 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

Eligibility criteria: Inclusion Criteria:general practitioner with an active practice in Flanders, Belgium -

Exclusion Criteria:other specialists in medicine

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Primary outcomes:
measure: number of respiratory tract infections
measure: number of influenza cases defined as a RTI with positive nose and throat swabs
measure: number of influenza cases defined as a RTI with 4-fold IgG titre rise
Secondary outcomes:
Other outcomes:
Locations:
Study officials:
affiliation: University of Antwerp, Department of family medicine
name: Barbara Michiels, Dr.
role: PRINCIPAL_INVESTIGATOR
References:
citation: Michiels B, Philips H, Coenen S, Yane F, Steinhauser T, Stuyck S, Denekens J, Van Royen P. The effect of giving influenza vaccination to general practitioners: a controlled trial [NCT00221676]. BMC Med. 2006 Jul 10;4:17. doi: 10.1186/1741-7015-4-17.