Zanamivir Versus Trivalent Split Virus Influenza Vaccine

Study Overview
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Brief Summary
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This unblinded pilot study is intended to assess the feasibility of a larger double-blind, randomized control trial. For the larger trial the investigators are interested in understanding the relative benefits of vaccine and antiviral prophylaxis, the risk factors for influenza infection in healthy adults, and in assessing the safety and tolerability of seasonal antiviral prophylaxis in healthcare workers. The pilot study will be assessing the rate of infection with influenza and the rate of adherence to long-term zanamivir in 60 healthy volunteers.

Detailed Description
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Several studies have demonstrated that zanamivir and oseltamivir are effective in preventing influenza infection and illness when used either as prophylaxis after exposure to a household contact with influenza or when taken for several weeks at the height of influenza activity in the general community. However, the longest duration of prophylaxis with neuraminidase inhibitors in two clinical trials, to date, has been six weeks. Antiviral medication will likely have an important role in the response to the next influenza pandemic. Additionally, there may be indications for use during seasons when the major infecting strain of influenza in not one whose antigen is well covered by the vaccine.

Official Title
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A Pilot Study for a Randomized Controlled Trial to Compare Trivalent Split Virus Influenza Vaccine to Seasonal Antiviral Prophylaxis in Healthcare and Other Healthy Adults: Assessment of Zanamivir Versus Vaccine (Stop-Flu-2)

Conditions
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Influenza

Intervention / Treatment
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* Biological: Fluviral
* Drug: Zanamivir


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 18-69 years old as of 01/Nov/2008 have an understanding of the study, agree to its provisions, and give written informed consent prior to study entry available for follow-up during the study period if a women of child-bearing years, must meet criteria to prevent pregnancy Exclusion Criteria: allergy to any component of influenza vaccine or zanamivir previous serious adverse event associated with influenza vaccination receipt of influenza vaccine between 01/Mar/2008 and start of study previous adverse event associated with the use of antiviral medications expecting to be unable to take zanamivir for more than 72 hours during study period planning to spend more than 2 consecutive weeks outside Canada or more than 100 km from the study site during study period pregnant, or planning to become pregnant, during study period breastfeeding, or planning to breastfeed, a child under 12 months of age during study period receipt of immunoglobulin within six months of study entry immunocompromising condition or therapy that would be expected to reduce the efficacy of vaccination plans to receive cytotoxic or radiation therapy during study period history of cardiovascular or pulmonary disease that has required hospital admission within the past year history of asthma or other chronic respiratory disease participating in a trial that will result in the receipt of an investigational medication during the period that zanamivir may be taken (15/Nov/2008 to 30/Apr/2009)

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 69 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: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Influenza vaccine<br>Influenza vaccine, using Fluviral trivalent split virus vaccine | Biological: Fluviral<br>* One dose<br>|
| Experimental: Antiviral prophylaxis<br>Zanamivir antiviral prophylaxis | Drug: Zanamivir<br>* 10 mg, OD, for duration of influenza season (10-23 weeks)<br>* Other names: Relenza;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of Laboratory Confirmed Influenza Infections | Four-fold increase in antibody titer 2 weeks post injection and end of study or positive laboratory test for influenza during study (polymerase chain reaction [PCR] or culture) | 6 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of Subjects Adhering to Long-term Zanamivir Prophylaxis | Number of subjects taking 80% or more doses per week of zanamivir (10 mg once daily), as influenza prophylaxis, for 13 weeks or longer (as measured by weekly diary and dose counts at study visits). | 5 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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antiviral drugs, influenza vaccines