RT Journal Article SR Electronic T1 Severity of COVID-19 among solid organ transplant recipients in Canada, 2020–2021: a prospective, multicentre cohort study JF Canadian Medical Association Journal JO CMAJ FD Canadian Medical Association SP E1155 OP E1163 DO 10.1503/cmaj.220620 VO 194 IS 33 A1 Hall, Victoria G. A1 Solera, Javier T. A1 Al-Alahmadi, Ghadeer A1 Marinelli, Tina A1 Cardinal, Heloise A1 Poirier, Charles A1 Huard, Geneviève A1 Prasad, G.V. Ramesh A1 De Serres, Sacha A. A1 Isaac, Debra A1 Mainra, Rahul A1 Lamarche, Caroline A1 Sapir-Pichhadze, Ruth A1 Gilmour, Susan A1 Humar, Atul A1 Kumar, Deepali YR 2022 UL http://www.cmaj.ca/content/194/33/E1155.abstract AB Background: Severe COVID-19 appears to disproportionately affect people who are immunocompromised, although Canadian data in this context are limited. We sought to determine factors associated with severe COVID-19 outcomes among recipients of organ transplants across Canada.Methods: We performed a multicentre, prospective cohort study of all recipients of solid organ transplants from 9 transplant programs in Canada who received a diagnosis of COVID-19 from March 2020 to November 2021. Data were analyzed to determine risk factors for oxygen requirement and other metrics of disease severity. We compared outcomes by organ transplant type and examined changes in outcomes over time. We performed a multivariable analysis to determine variables associated with need for supplemental oxygen.Results: A total of 509 patients with solid organ transplants had confirmed COVID-19 during the study period. Risk factors associated with needing (n = 190), compared with not needing (n = 319), supplemental oxygen included age (median 62.6 yr, interquartile range [IQR] 52.5–69.5 yr v. median 55.5 yr, IQR 47.5–66.5; p < 0.001) and number of comorbidities (median 3, IQR 2–3 v. median 2, IQR 1–3; p < 0.001), as well as parameters associated with immunosuppression. Recipients of lung transplants (n = 48) were more likely to have severe disease with a high mortality rate (n = 15, 31.3%) compared with recipients of other organ transplants, including kidney (n = 48, 14.8%), heart (n = 1, 4.4%), liver (n = 9, 11.4%) and kidney–pancreas (n = 3, 12.0%) transplants (p = 0.02). Protective factors against needing supplemental oxygen included having had a liver transplant and receiving azathioprine. Having had 2 doses of SARS-CoV-2 vaccine did not have an appreciable influence on oxygen requirement. Multivariable analysis showed that older age (odds ratio [OR] 1.04, 95% confidence interval [CI] 1.02–1.07) and number of comorbidities (OR 1.63, 95% CI 1.30–2.04), among other factors, were associated with the need for supplemental oxygen. Over time, disease severity did not decline significantly.Interpretation: Despite therapeutic advances and vaccination of recipients of solid organ transplants, evidence of increased severity of COVID-19, in particular among those with lung transplants, supports ongoing public health measures to protect these at-risk people, and early use of COVID-19 therapies for recipients of solid organ transplants.