tetano
Editor, Senior Moderator
Influenza Other Respir Viruses
. 2026 Mar;20(3):e70222.
doi: 10.1111/irv.70222.
Effectiveness of 2024/25 KP.2 Vaccine Against Outpatient COVID-19 in Canada
Lea Separovic[SUP] 1 [/SUP], Suzana Sabaiduc[SUP] 1 [/SUP], Yuping Zhan[SUP] 1 [/SUP], Samantha E Kaweski[SUP] 1 [/SUP], Sara Carazo[SUP] 2 [/SUP], Romy Olsha[SUP] 3 [/SUP], Richard G Mather[SUP] 3 4 [/SUP], Christine Lacroix[SUP] 2 [/SUP], Maan Hasso[SUP] 3 [/SUP], Inès Levade[SUP] 2 [/SUP], Isabelle Meunier[SUP] 2 [/SUP], Agatha N Jassem[SUP] 1 [/SUP], Katie Dover[SUP] 1 [/SUP], Ruimin Gao[SUP] 5 [/SUP], Nathalie Bastien[SUP] 5 [/SUP], Danuta M Skowronski[SUP] 1 6 [/SUP]
Affiliations
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.
Keywords: COVID‐19; public health; respiratory illness; vaccine effectiveness; vaccines.
. 2026 Mar;20(3):e70222.
doi: 10.1111/irv.70222.
Effectiveness of 2024/25 KP.2 Vaccine Against Outpatient COVID-19 in Canada
Lea Separovic[SUP] 1 [/SUP], Suzana Sabaiduc[SUP] 1 [/SUP], Yuping Zhan[SUP] 1 [/SUP], Samantha E Kaweski[SUP] 1 [/SUP], Sara Carazo[SUP] 2 [/SUP], Romy Olsha[SUP] 3 [/SUP], Richard G Mather[SUP] 3 4 [/SUP], Christine Lacroix[SUP] 2 [/SUP], Maan Hasso[SUP] 3 [/SUP], Inès Levade[SUP] 2 [/SUP], Isabelle Meunier[SUP] 2 [/SUP], Agatha N Jassem[SUP] 1 [/SUP], Katie Dover[SUP] 1 [/SUP], Ruimin Gao[SUP] 5 [/SUP], Nathalie Bastien[SUP] 5 [/SUP], Danuta M Skowronski[SUP] 1 6 [/SUP]
Affiliations
- PMID: 41784466
- PMCID: PMC12962023
- DOI: 10.1111/irv.70222
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.
Keywords: COVID‐19; public health; respiratory illness; vaccine effectiveness; vaccines.