Sentinel Practitioner Surveillance Network (SPSN) — Vaccine Effectiveness Program

Why Participate?

We rely on sentinels to help us monitor respiratory virus activity across Ontario in community outpatient settings and evaluate the performance of seasonal influenza, COVID-19, and RSV vaccines.

Your participation also contributes towards:

• Informing provincial and national vaccination strategies and the World Health Organization’s (WHO) recommendations for the seasonal influenza vaccine composition in the northern hemisphere
• Data-driven patient care with timely results regarding your patient’s diagnosis
• Bringing valuable knowledge to your practice with a better grasp of respiratory virus activity in the community

Who Can Participate?

Sentinels (primary care practitioners including family physicians and nurses in the extended class/nurse practitioners) can sign up annually to be a part of the SPSN.

How to Participate?

Complete the Consent Form and submit by email to spsn.on@oahpp.ca, or by fax to (416) 596-1799, Attn: SPSN program.

Compensation

At the end of the season, you will be compensated $20 per specimen sent to the laboratory with a completed short questionnaire.

This page contains information for sentinels on collecting specimens, completing the requisition form, transporting specimens and receiving results. See the Instruction Sheet for full details.

Collecting Specimens

• Wear appropriate Personal Protective Equipment to protect yourself.
• Ask patients who have copious discharge or mucus to gently clean their nose with a tissue.
• Collect an appropriate nasopharyngeal (preferred) or deep nasal specimen.
• Place the swab into the accompanying vial of universal transport medium. Break the swab at its break point so the swab stays in the vial. Secure the lid.
• Label the vial with the patient’s full name and date of birth. Place the specimen in the biohazard bag provided and seal the specimen pocket of the bag using the adhesive strip.
• Refrigerate at 4°C and transport to the lab within 72 hours.

Completing the Requisition Form

Complete all fields of the SPSN – Vaccine Effectiveness Test Requisition Form provided:

• Fill out a new form for each submitted specimen.
• Under clinician/referring laboratory, enter the full name and billing address of the practitioner/facility to which the final report will be sent.
• Enter the specimen collection date in the appropriate box.
• Complete the questionnaire to help assess vaccine effectiveness in protecting against laboratory-confirmed influenza/COVID-19/RSV.
• For each specimen, place the corresponding requisition form on the outside pocket of the biohazard bag.
• Use one biohazard bag for each specimen and the corresponding completed requisition form.

Transporting Specimens

• Submit SPSN specimens to PHO via your usual lab submission route within 72 hours of collection. Ensure with your lab-service provider that specimens will be delivered to PHO for testing.

Reporting Results

Results will be reported directly to the submitter’s office. You will receive results from the Laboratory Information System using the AutoFax system. To register for AutoFax, call PHO’s Customer Service Centre at 416-235-6556 or 1-877-604-4567.

Results will also be transmitted to the Ontario Laboratory Information System (OLIS) and can be accessed there.

Current Publication List

1. Separovic L, Zhan Y, Kaweski SE, Sabaiduc S, Carazo S, Olsha R, et al. Interim estimates of vaccine effectiveness against influenza A(H1N1)pdm09 and A(H3N2) during a delayed influenza season, Canada, 2024/25. Euro Surveill. 2025;30(4). Available from: https://doi.org/10.2807/1560-7917.ES.2025.30.4.2500059

    

2. Skowronski DM, Zhan Y, Kaweski SE, Sabaiduc S, Khalid A, Olsha R, et al. 2023/24 mid-season influenza and Omicron XBB.1.5 vaccine effectiveness estimates from the Canadian Sentinel Practitioner Surveillance Network (SPSN). Euro Surveill. 2024 Feb;29(7). Available from: http://doi.org/10.2807/1560-7917.ES.2024.29.7.2400076

    

3. Skowronski DM, Chuang ESY, Sabaiduc S, Kaweski SE, Kim S, Dickinson JA, et al. Vaccine effectiveness estimates from an early-season influenza A(H3N2) epidemic, including unique genetic diversity with reassortment, Canada, 2022/23. Euro Surveill. 2023;28(5). Available from: https://doi.org/10.2807/1560-7917.ES.2023.28.5.2300043

    

4. Shinhye K, Chuang ESY, Sabaiduc S, Olsha R, Kaweski SE, Zelyas N, et al. Influenza vaccine effectiveness against A(H3N2) during the delayed 2021/22 epidemic in Canada. Euro Surveill. 2022;27(38). Available from:https://doi.org/10.2807/1560-7917.ES.2022.27.38.2200720

    

5. Skowronski DM, Zou M, Sabaiduc S, Murti M, Olsha R, Dickinson JA, et al. Interim estimates of 2019/20 vaccine effectiveness during early-season co-circulation of influenza A and B viruses, Canada, February 2020. Euro Surveill. 2020;25(7). Available from: https://doi.org/10.2807/1560-7917.ES.2020.25.7.2000103

    

6. Skowronski DM, Zou M, Clarke Q, Chambers C, Dickinson JA, Sabaiduc S, et al. Influenza vaccine does not increase the risk of coronavirus or other noninfluenza respiratory viruses: retrospective analysis from Canada, 2010–2011 to 2016–2017. Clin Infect Dis. 2020;71(16):2285-8. Available from: https://doi.org/10.1093/cid/ciaa626

    

7. Skowronski DM, Leir S, Sabaiduc S, Chambers C, Zou M, Rose C, et al. Influenza vaccine effectiveness by A(H3N2) phylogenetic subcluster and prior vaccination history: 2016–2017 and 2017–2018 epidemics in Canada. J Infect Dis. 2022;225(8):1387-98. Available from: https://doi.org/10.1093/infdis/jiaa138

    

8. Skowronski DM, Sabaiduc S, Leir S, Rose C, Zou M, Murti M, et al. Paradoxical clade- and age-specific vaccine effectiveness during the 2018/19 influenza A(H3N2) epidemic in Canada: potential imprint-regulated effect of vaccine (I-REV). Euro Surveill. 2019;24(46). Available from: https://doi.org/10.2807/1560-7917.ES.2019.24.46.1900585

    

9. Skowronski DM, Leir S, Sabaiduc S, Murti M, Dickinson JA, Olsha R, et al. Interim estimates of 2018/19 vaccine effectiveness against influenza A(H1N1)pdm09, Canada, January 2019. Euro Surveill. 2019;24(4). Available from: https://doi.org/10.2807/1560-7917.ES.2019.24.4.1900055

    

10. Skowronski DM, Chambers C, De Serres G, Dickinson JA, Winter AL, Hickman R, et al. Early season co-circulation of influenza A(H3N2) and B(Yamagata): interim estimates of 2017/18 vaccine effectiveness, Canada, January 2018. Euro Surveill. 2018;23(5). Available from:  https://doi.org/10.2807/1560-7917.ES.2018.23.5.18-00035

     

2025–2026 Northern Hemisphere Recommendations for Influenza Vaccines:

• Egg-based vaccines:
  
  • A/Victoria/4897/2022 (H1N1)pdm09-like virus
  • A/Croatia/10136RV/2023 (H3N2)-like virus
  • B/Austria/1359417/2021 (B/Victoria lineage)-like virus

• Cell culture, recombinant protein- or nucleic acid-based vaccines:
  
  • A/Wisconsin/67/2022 (H1N1)pdm09-like virus
  • A/District of Columbia/27/2023 (H3N2)-like virus
  • B/Austria/1359417/2021 (B/Victoria lineage)-like virus

• Quadrivalent B/Yamagata:
  
  • a B/Phuket/3073/2013 (B/Yamagata lineage)-like virus

SPSN influenza seasonal updates will resume at the start of the 2025–26 respiratory reason. For current respiratory trends in Ontario, explore PHO’s Ontario Respiratory Virus Tool.

For global respiratory trends, explore World Health Organization’s influenza and other respiratory updates.

How many respiratory specimens should be collected by each sentinel practitioner?

This may vary, however based on statistical power calculations and experience from several influenza seasons, it is anticipated that a minimum of one to two specimens per week may be submitted by each sentinel practitioner over the course of the SPSN surveillance period for a total of 20-25 specimens per season. In the national collaboration between British Columbia, Alberta, Ontario and Quebec, we are aiming for a total of 5,500 respiratory specimens as part of this program.

When should I start collecting specimens from patients presenting with symptoms of influenza-like illness (ILI) or acute respiratory illness (ARI) this year? When do I stop?

You can start submitting specimens as soon as you receive the information package and testing kits. Please continue to submit samples until notified by the SPSN coordinator to stop.

Which patients are eligible for inclusion?

Any patient who is a resident of Ontario, who presents in your practice with symptoms of an influenza-like illness (ILI) or acute respiratory illness (ARI) within one week of symptom onset.

You should collect a nasopharyngeal or nasal swab using the test kits provided by the SPSN. You will be notified if specimen collection for the purpose of the SPSN will change. Please note that it is important that you collect respiratory specimens from eligible patients presenting within seven days of ILI or ARI onset, whether or not they received the influenza vaccine.

Should I submit SPSN specimens to the laboratory where I usually send respiratory specimens?

Yes. Sentinels can submit SPSN specimens to PHO via their routine lab submission process. Specimens will be directed to PHO by your laboratory. It is advised to inform your lab-service provider that SPSN specimens should be forwarded to PHO and not tested by other labs. Please ensure that a fully completed SPSN requisition is submitted with each specimen. For more information on this please refer to Tab 3: Submitting Specimens.

Will I be compensated for my time?

Yes. As your time, effort and participation are much appreciated, participating sentinels will be compensated $20 for each specimen submitted with a completed SPSN-specific requisition.

Reimbursement will be made at the end of each period.

Has this study received ethics approval and if so, what special ethics requirements are there?

The SPSN’s methodology has been reviewed by ethics boards in each participating province every year since 2004. Since 2024 ethics review and approval has been granted in Alberta while SPSN activities in British Columbia, Quebec, and Ontario are considered routine public health practice. These activities were conducted in fulfilment of PHO’s legislated mandate.

As part of the program, sentinel physicians and nurse practitioners are required to inform their eligible patients and elicit verbal consent to participate through specimen collection and questionnaire completion. A verbal consent script has been drafted by SPSN investigators for this purpose and is included with the study material sent to consenting sentinels

Who else is involved in this study?

In each participating province (ON, BC, AB, QC), a team of epidemiologists and laboratory investigators has been established. These investigators have collaborated for several years and Ontario investigators and sentinels will again join that team this season.

How will vaccine effectiveness be calculated?

Vaccine effectiveness against laboratory confirmed viral infection (e.g. influenza or COVID-19) is calculated by SPSN researchers based on a case control design. Using the laboratory results (either positive or negative for the investigated viral pathogen) and the answers to the questions accompanying the laboratory requisition (e.g., recent immunization history), vaccine status is compared for those with and without the viral illness. The program is based on the understanding that not everyone with ILI or ARI will have the specific virus estimated. Those who test positive for that virus are counted as cases, whereas those who test negative for the virus become the controls. Immunization rates among these two groups are used for VE estimation.

Where will this analysis be done nationally and how will confidentiality be preserved?

Since 2004, an overall vaccine effectiveness result has been calculated for all participating provinces combined nationally through statistical analysis at the British Columbia Centre for Disease Control (BCCDC).

Data from Quebec, Ontario, and Alberta that are shared with BCCDC do not include any personal identifiers and chronic medical conditions, as previously specified by ethics boards. Personal identifying information will not be transmitted. Only the influenza test result and relevant epidemiologic information provided on the requisition are shared for the sole purpose of calculating an aggregate vaccine effectiveness result. At each level, all data is stored in a secure and locked facility. Dr. Danuta Skowronski, principal investigator, is located at the BCCDC.

Do I need special equipment for the study?

You will need:

• Test kits (provided by PHO’s SPSN team).
• A fridge to store specimens at 4°C until transported to lab. Specimens should be shipped within 72 hours of collection.

How do I receive results for specimens I submitted?

In order to reduce the turnaround time and increase the efficiency of testing and reporting, results will be reported automatically by the Laboratory Information System using the AutoFax system. To register for AutoFax, please contact the Toronto Public Health Laboratory’s Customer Service Centre at 416-235-6556 or 1-877-604-4567.

PHO’s laboratory also transmits the results to the Ontario Laboratory Information System (OLIS) and they can be accessed there.

Where can I get more information about what else is circulating in my area?

Refer to the Ontario Respiratory Virus Tool for more information.

How can I contact the SPSN team?

By email: spsn.on@oahpp.ca
By phone: (647) 792-3187
By mail:
Sentinel Practitioner Surveillance Network
Public Health Ontario
661 University Avenue, Suite 1701
Toronto, ON
M5G 1M1

If you are interested in the SPSN, your signed sentinel consent form can be submitted by email to spsn.on@oahpp.ca or faxed to (416) 596-1799.