Effectiveness of 2024/25 KP.2 Vaccine Against Outpatient COVID‐19 in Canada

Lea Separovic; Suzana Sabaiduc; Yuping Zhan; Samantha E. Kaweski; Sara Carazo; Romy Olsha; Richard G. Mather; Christine Lacroix; Maan Hasso; Inès Levade; Isabelle Meunier; Agatha N. Jassem; Katie Dover; Ruiqing Gao; Nathalie Bastien; Danuta M. Skowronski

doi:10.1111/irv.70222

journal article Open Access Mar 01, 2026

Effectiveness of 2024/25 KP.2 Vaccine Against Outpatient COVID‐19 in Canada

Lea Separovic Suzana Sabaiduc Yuping Zhan Samantha E. Kaweski Sara Carazo Romy Olsha Richard G. Mather Christine Lacroix Maan Hasso Inès Levade Isabelle Meunier Agatha N. Jassem Katie Dover Ruiqing Gao Nathalie Bastien Danuta M. Skowronski

Influenza and Other Respiratory Viruses Vol. 20 No. 3 · Wiley

View at Publisher Save 10.1111/irv.70222

Abstract

ABSTRACT
The Canadian Sentinel Practitioner Surveillance Network used the test‐negative design to assess KP.2 vaccine effectiveness (VE) against medically attended outpatient COVID‐19 between November 2024 and April 2025 among participants ≥ 12 years. Analyses included 5410 controls (19% vaccinated) and 435 COVID‐19 cases (10% vaccinated). Nearly three‐quarters (72%) of contributing case viruses were genetically characterized, with XEC (35%) and KP.3.1.1 (38%) variants most commonly identified. Vaccination reduced COVID‐19 risk by approximately half (54%; 95% CI: 36–68) relative to unvaccinated individuals. VE was greatest during the first 2 months postvaccination, reducing risk by two‐thirds and declining to minimal protection by the fifth month postvaccination.

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Citations

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References

Details

Published: Mar 01, 2026
Vol/Issue: 20(3)
License: View

Authors

L

Lea Separovic

British Columbia Centre for Disease Control Vancouver Canada

S

Suzana Sabaiduc

British Columbia Centre for Disease Control Vancouver Canada

Y

Yuping Zhan

British Columbia Centre for Disease Control Vancouver Canada

S

Samantha E. Kaweski

British Columbia Centre for Disease Control Vancouver Canada

S

Sara Carazo

Institut National de Santé Publique du Québec Québec Canada

R

Romy Olsha

Public Health Ontario Toronto Canada

R

Richard G. Mather

Public Health Ontario Toronto Canada; Queen's University Kingston Canada

C

Christine Lacroix

Institut National de Santé Publique du Québec Québec Canada

M

Maan Hasso

Public Health Ontario Toronto Canada

I

Inès Levade

Institut National de Santé Publique du Québec Québec Canada

I

Isabelle Meunier

Institut National de Santé Publique du Québec Québec Canada

A

Agatha N. Jassem

British Columbia Centre for Disease Control Vancouver Canada

K

Katie Dover

British Columbia Centre for Disease Control Vancouver Canada

R

Ruiqing Gao

National Microbiology Laboratory, Public Health Agency of Canada Winnipeg Canada

N

Nathalie Bastien

National Microbiology Laboratory, Public Health Agency of Canada Winnipeg Canada

D

Danuta M. Skowronski

British Columbia Centre for Disease Control Vancouver Canada; University of British Columbia Vancouver Canada

Funding

Public Health Agency of Canada Award: 2324‐HQ‐000038

Cite This Article

Lea Separovic, Suzana Sabaiduc, Yuping Zhan, et al. (2026). Effectiveness of 2024/25 KP.2 Vaccine Against Outpatient COVID‐19 in Canada. Influenza and Other Respiratory Viruses, 20(3). https://doi.org/10.1111/irv.70222

Effectiveness of 2024/25 KP.2 Vaccine Against Outpatient COVID‐19 in Canada

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