The influenza immunization program is the largest, most costly immunization program in Canada. More than 10 million doses of the influenza vaccine are administered to Canadians each year and hundreds of millions of doses are administered globally. The return on this enormous investment critically depends upon how well the vaccine works against the viruses that ultimately circulate during the winter.

Given the enormous burden of illness due to influenza and the considerable uncertainty in vaccine match each year, public health experts needed an efficient and valid way to monitor influenza vaccine effectiveness. Although randomized controlled trials are considered the gold standard, they are not practical for the influenza vaccine because of cost, time, and ethical concerns with giving placebos instead of recommended vaccines.

In 2004, Dr. Danuta Skowronski of the BC Centre for Disease Control introduced an epidemiologic method called the Test-Negative Design that would enable rapid and reliable assessment of influenza vaccine effectiveness to inform public health communications in real-time. The Test-Negative Design has been proven valid in direct head-to-head comparison with estimates from randomized controlled trials and has been adopted by more than 25 countries across 4 continents as part of an international consortium called the Global Influenza Vaccine Effectiveness (GIVE) network.

The benefits of the Test-Negative Design method are multifaceted: not only does it allow for real-time collection of data to inform current season vaccine effectiveness and real-time public health messaging, it also helps improve our understanding of vaccine-virus relatedness to predict vaccine protection in subsequent seasons.

Physicians interested in joining the Sentinel Physician Surveillance Network can email or call or telephone: 604-707-2531. More information can be found online at

Contact Information:

Title: Physician, Epidemiologist

Contact information:

← Back to Search Results

Leading Practices are submitted by health organizations from around the world. The contents of the Leading Practices library do not reflect opinions or views of HSO or its affiliates. If you have questions, concerns or suggestions please email us at