The Canadian Sentinel Practitioner Surveillance Network (SPSN) for community-based respiratory virus and vaccine effectiveness (VE) monitoring: a multidisciplinary surveillance and science platform for preparedness, rapid research and response to emerging or re-emerging pathogens, seasonal epidemics and pandemics.

The Canadian Sentinel Practitioner Surveillance Network (SPSN) is a combined surveillance and science platform for respiratory virus and vaccine effectiveness (VE) monitoring. The SPSN links hundreds of community-based primary care practitioners to epidemiologists, public health specialists, virologists and genome scientists in BC, Alberta, Ontario, and Quebec. Sentinels collect respiratory specimens from patients with acute respiratory illness (ARI), and complete brief illness and immunization questionnaires. These are submitted to public health laboratories where specimens are tested for up to 20 different respiratory pathogens. Linking test results and vaccine information, the SPSN generates estimates of how well vaccines are working and explores why VE is sometimes suboptimal against highly changeable viruses such as influenza. Using genomic tools, the SPSN studies emergence and impact of new variants and has made important discoveries such as the effects of egg-based manufacturing, repeated vaccination, novel pandemic vaccine technologies, and the effects of first childhood infection (imprinting) on the lifelong seasonal and pandemic risk of influenza viruses. The SPSN's longstanding experience in rapid response research make it nimble to address emerging public health threats and needs, including both pandemics of the 21st century. The SPSN continues to monitor COVID-19, including VE of the fall vaccine against emerging variants and waning protection to inform spring booster doses. Currently, the world is witnessing unprecedented spread of avian influenza A(H5N1) in animals. Rare human cases have occurred in North America, making this virus a leading threat requiring broad community-based surveillance in case it also establishes pandemic spread. In that context, reinforcing the SPSN and its hundreds of front-line practitioners who are keeping steady watch on trends and causes of ARI in communities has never been more important to Canadian pandemic readiness.