Does Seasonal Influenza Vaccination Affect the Incidence of pH1N1 Influenza?
Since the onset of the 2009 pandemic, several observational public health investigations in Canada have identified evidence that suggests that adults, particularly younger adults, who have previously received seasonal influenza vaccine are at increased risk of infection with the 2009 pandemic strain of H1N1 (pH1N1). Investigations in Australia, the United States and the United Kingdom have not identified this effect. While it is not possible to have an answer to whether this affect is real prior to the second wave of the 2009 pandemic, it remains vital to future influenza vaccination programs that the hypothesis that, in 2009, seasonal vaccine increases or decreases the risk of pH1N1 infection be confirmed or refuted.
The objective of this study is to determine whether Ontario adults aged 18-60 years who receive the 2009 seasonal influenza vaccine will be at a 2 fold or greater increased risk of infection with influenza pH1N1 during the second or third wave of the 2009 pandemic.
|Influenza||Biological: Fluviral influenza vaccine, 2009-2010 Biological: Normal saline||Phase 3|
|Study Design:||Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double Blind (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Health Services Research
|Official Title:||A Randomized Controlled Trial of the Effect of Seasonal Influenza Vaccination on the Incidence of Infection Due to the 2009 H1N1 Influenza|
- Number of pH1N1 Influenza Infections as Diagnosed by PCR From Mid-turbinate Swab [ Time Frame: day +7 post seasonal influenza vaccination (or placebo) to end of study ]Influenza infection (pH1N1) as diagnosed by PCR from self-collected mid-turbinate swab. Participant is asked to collect a swab when they have symptoms possibly compatible with an acute viral respiratory illness: 1) fever without another obvious source, 2) at least two new respiratory symptoms (runny or stuffy nose, sneezing, sore or scratchy throat, hoarseness, cough), or 3) one respiratory symptom (as above) and one systemic symptom (fever, malaise, muscle aches, headache, fatigue)
|Study Start Date:||October 2009|
|Study Completion Date:||July 2010|
|Primary Completion Date:||March 2010 (Final data collection date for primary outcome measure)|
Experimental: Seasonal influenza vaccination
Receipt of Fluviral seasonal (2009-2010, Canadian) influenza vaccination as per manufacturers specification
Biological: Fluviral influenza vaccine, 2009-2010
0.5 mL intramuscular
Placebo Comparator: Placebo
0.5 mL normal saline
Biological: Normal saline
0.5 mL intramuscular
This study will be an observer -blind randomized controlled trial.
This study will primarily recruit patients from an existing cohort of adult health care and other workers in Toronto, as of September 15, 2009, almost 1000 adults are participating in this cohort; with approximately 75 new cohort members being recruited weekly (target is 1300). Recruitment will be supplemented by enrollment at Hamilton Health Sciences Centre (N~3920 employees plus physicians & midwives) and Queen Elizabeth II Health Centre in Halifax (N~6000 employees plus physicians & midwives).
To date, health care workers in the Toronto cohort have been recruited at the Mount Sinai Hospital, Toronto East General Hospital, and North York General Hospital. Recruitment is just beginning at Sunnybrook Health Sciences Centre, and the University Health Network.
Non-health care workers are being recruited from several large Toronto employers of primarily office workers. These include the Ontario Agency for Health Protection and Promotion, the head offices of the Ontario Power Generation Corporation, the Art Gallery of Ontario, and the head offices of Scotia Bank. Non-health care workers should meet inclusion criteria and should not work primarily with children or from a home office.
Participants in the study are completing web-based diaries weekly, and, whenever they develop symptoms possibly compatible with influenza, are submitting nasal swabs, and completing symptom diaries daily while ill. Nasal swabs are tested by polymerase chain reaction (PCR) on a same or next day basis with antivirals prescribed to participants who develop influenza.
Please refer to this study by its ClinicalTrials.gov identifier: NCT01001325
|North York General Hospital|
|North York, Ontario, Canada, M2K 1E1|
|Mount Sinai Hospital|
|Toronto, Ontario, Canada, M5G 1X5|
|Principal Investigator:||Allison J McGeer, MD||Mount Sinai Hospital, New York|
|Principal Investigator:||Brenda L. Coleman, PhD||Mount Sinai Hospital, New York|
|Principal Investigator:||Natasha Crowcroft, MD||Ontario Agency for Health Protection & Promotion|
|Study Director:||Karen Green, MSc||Mount Sinai Hospital, New York|
|Study Director:||Kevin Katz, MD||North York General Hospital|
|Study Director:||Mark Loeb, MD||Hamilton Health Sciences Centre|
|Study Director:||Donald Low, MD||Mount Sinai Hospital, New York|
|Study Director:||Shelly McNeil, MD||Queen Elizabeth II Health Sciences Centre|
|Study Director:||Matthew Muller, MD, PhD||St. Michael's Hospital, Toronto|
|Study Director:||Andrew Simor, MD||Sunnybrook Health Sciences Centre|