tetano
Editor, Senior Moderator
Influenza Other Respir Viruses
. 2026 Jan;20(1):e70197.
doi: 10.1111/irv.70197. Early COVID-19 and Severity of Subsequent Omicron Infection in Ontario Canada
Caroline Kassee[SUP] 1 [/SUP], Altynay Shigayeva[SUP] 1 [/SUP], Christopher Kandel[SUP] 2 3 [/SUP], Lubna Farooqi[SUP] 1 [/SUP], Zoe Zhong[SUP] 1 [/SUP], Anne-Claude Gingras[SUP] 4 5 [/SUP], Brenda L Coleman[SUP] 1 6 [/SUP], Lois Gilbert[SUP] 1 [/SUP], Wayne L Gold[SUP] 3 7 [/SUP], Maria Major[SUP] 8 [/SUP], Tony Mazzulli[SUP] 1 9 [/SUP], Samira Mubareka[SUP] 9 10 [/SUP], Srinivas Rao Valluri[SUP] 11 [/SUP], Catherine Martin[SUP] 11 [/SUP], Moe H Kyaw[SUP] 11 [/SUP], John M McLaughlin[SUP] 11 [/SUP], Allison McGeer[SUP] 1 4 6 9 [/SUP]
Affiliations
We evaluated whether having early COVID-19 reduced the severity of subsequent Omicron infection, assessing activities of daily living (ADL), healthcare utilization and illness duration. Comparisons were made between persons with (1) early COVID-19-compatible illness with a negative test, (2) early lab-confirmed SARS-CoV-2 14-26 months and (3) early lab-confirmed SAR-CoV-2 > 26 months before Omicron infection. Among 261 patients with laboratory-confirmed Omicron, 177 (68%) had COVID-19 in 2020, a median of 793 days (IQR, 659-902) prior to Omicron infection. Compared to no early COVID-19, COVID-19 14-26 months, but not > 26 months, before was associated with reduced impact on ADL during first Omicron infection (OR 0.52, 95% CI 0.29-0.93).
Keywords: Omicron; activities of daily living (ADL); pre‐existing immunity; prior infection; reinfection; severity.
. 2026 Jan;20(1):e70197.
doi: 10.1111/irv.70197. Early COVID-19 and Severity of Subsequent Omicron Infection in Ontario Canada
Caroline Kassee[SUP] 1 [/SUP], Altynay Shigayeva[SUP] 1 [/SUP], Christopher Kandel[SUP] 2 3 [/SUP], Lubna Farooqi[SUP] 1 [/SUP], Zoe Zhong[SUP] 1 [/SUP], Anne-Claude Gingras[SUP] 4 5 [/SUP], Brenda L Coleman[SUP] 1 6 [/SUP], Lois Gilbert[SUP] 1 [/SUP], Wayne L Gold[SUP] 3 7 [/SUP], Maria Major[SUP] 8 [/SUP], Tony Mazzulli[SUP] 1 9 [/SUP], Samira Mubareka[SUP] 9 10 [/SUP], Srinivas Rao Valluri[SUP] 11 [/SUP], Catherine Martin[SUP] 11 [/SUP], Moe H Kyaw[SUP] 11 [/SUP], John M McLaughlin[SUP] 11 [/SUP], Allison McGeer[SUP] 1 4 6 9 [/SUP]
Affiliations
- PMID: 41527184
- DOI: 10.1111/irv.70197
We evaluated whether having early COVID-19 reduced the severity of subsequent Omicron infection, assessing activities of daily living (ADL), healthcare utilization and illness duration. Comparisons were made between persons with (1) early COVID-19-compatible illness with a negative test, (2) early lab-confirmed SARS-CoV-2 14-26 months and (3) early lab-confirmed SAR-CoV-2 > 26 months before Omicron infection. Among 261 patients with laboratory-confirmed Omicron, 177 (68%) had COVID-19 in 2020, a median of 793 days (IQR, 659-902) prior to Omicron infection. Compared to no early COVID-19, COVID-19 14-26 months, but not > 26 months, before was associated with reduced impact on ADL during first Omicron infection (OR 0.52, 95% CI 0.29-0.93).
Keywords: Omicron; activities of daily living (ADL); pre‐existing immunity; prior infection; reinfection; severity.