HLA and red blood cell antigen genotyping in SARS-CoV-2 convalescent plasma donors.

Aim: More data is required regarding the association between HLA allele and red blood cell (RBC) antigen expression in regard to SARS-CoV-2 infection and COVID-19 susceptibility. Methods: ABO, RhD, 37 other RBC antigens and HLA-A, B, C, DRB1, DQB1 and DPB1 were determined using high throughput platforms in 90 Caucasian convalescent plasma donors. Results: The AB group was significantly increased (1.5×, p = 0.018) and some HLA alleles were found to be significantly overrepresented (HLA-B*44:02, C*05:01, DPB1*04:01, DRB1*04:01 and DRB1*07:01) or underrepresented (A*01:01, B51:01 and DPB1*04:02) in convalescent individuals compared with the local bone marrow registry population. Conclusion: Our study of infection-susceptible but non-hospitalized Caucasian COVID-19 patients contributes to the global understanding of host genetic factors associated with SARS-CoV-2 infection and severity.

Incidence of SARS-CoV-2 Infection Among People Experiencing Homelessness in Toronto, Canada.

Importance: People experiencing homelessness are at high risk of SARS-CoV-2 infection. Incident infection rates have yet to be established in these communities and are needed to inform infection prevention guidance and related interventions. Objective: To quantify the SARS-CoV-2 incident infection rate among people experiencing homelessness in Toronto, Canada, in 2021 and 2022 and to assess factors associated with incident infection. Design, Setting, and Participants: This prospective cohort study was conducted among individuals aged 16 years and older who were randomly selected between June and September 2021 from 61 homeless shelters, temporary distancing hotels, and encampments in Toronto, Canada. Exposures: Self-reported housing characteristics, such as number sharing living space. Main Outcomes and Measures: Prevalence of prior SARS-CoV-2 infection in summer 2021, defined as self-reported or polymerase chain reaction (PCR)- or serology-confirmed evidence of infection at or before the baseline interview, and SARS-CoV-2 incident infection, defined as self-reported or PCR- or serology-confirmed infection among participants without history of infection at baseline. Factors associated with infection were assessed using modified Poisson regression with generalized estimating equations. Results: The 736 participants (415 of whom did not have SARS-CoV-2 infection at baseline and were included in the primary analysis) had a mean (SD) age of 46.1 (14.6) years; 486 (66.0%) self-identified as male. Of these, 224 (30.4% [95% CI, 27.4%-34.0%]) had a history of SARS-CoV-2 infection by summer 2021. Of the remaining 415 participants with follow-up, 124 experienced infection within 6 months, representing an incident infection rate of 29.9% (95% CI, 25.7%-34.4%), or 5.8% (95% CI, 4.8%-6.8%) per person-month. Report after onset of the SARS-CoV-2 Omicron variant was associated with incident infection, with an adjusted rate ratio (aRR) of 6.28 (95% CI, 3.94-9.99). Other factors associated with incident infection included recent immigration to Canada (aRR, 2.74 [95% CI, 1.64-4.58]) and alcohol consumption over the past interval (aRR, 1.67 [95% CI, 1.12-2.48]). Self-reported housing characteristics were not significantly associated with incident infection. Conclusions and Relevance: In this longitudinal study of people experiencing homelessness in Toronto, SARS-CoV-2 incident infection rates were high in 2021 and 2022, particularly once the Omicron variant became dominant in the region. Increased focus on homelessness prevention is needed to more effectively and equitably protect these communities.

Family physician virtual care during COVID-19 in London-Middlesex, Ontario, Canada: a mixed methods exploration.

Context: On March 14, 2020, the Ontario, Canada health insurance plan approved COVID-19 physician virtual billing codes; family physicians (FPs) rapidly adopted a new model of care. Virtual care may remain post-pandemic; however, its future should be informed by evidence that considers access and continuity. Objective: 1) to determine FP virtual visit volumes and patient characteristics and 2) to explore FPs' perspectives on virtual visit adoption and implementation. Study Design: Mixed methods: Secondary analysis of health administrative (HA) data and semi-structured qualitative interviews with FPs. Setting or Dataset: London and Middlesex County, Ontario, Canada. HA data through ICES, Ontario entity holding data. Population studied: FPs and their patients. Outcome Measures: Volumes of FP in-person and virtual visits during early pandemic; characteristics of patients receiving care; FPs' perspectives on adopting and delivering virtual care. Results: Overall visit volume dropped by 36% during first wave, recovered to pre-pandemic levels by October 2020. Sharp in-person visit drop of 73% and virtual visit uptake from 0.08% of total visits to 57% within two weeks of March 2020. FPs described this initial drop in volume as patients not seeking care and practices lacking PPE. The move to virtual care was largely to telephone visits. Patient characteristics compared to pre-pandemic, the proportion seeking care were older (46 vs 50 years), more vulnerable (38% vs 41%), and more multimorbidity (33% vs 41%). This was consistent with FP reports that healthier patients stayed away, routine care deferred, sicker patients needed to be seen. FPs believed most vulnerable patients had access to care but cautioned highly vulnerable such as those homeless did not have cell phone access or a safe place to receive calls. Rural FPs reported access issues because of lack of high-speed internet. FPs attributed success of virtual care to the continuity in relationships they had with patients that were established in person pre-pandemic. Conclusions: FPs moved rapidly to virtual care. FP offices remained open despite PPE concerns but overall volumes dropped initially. Vulnerable and sicker patients received care but FPs expressed concern for highly vulnerable and rural residents. FPs believed they could offer patient-centred care over the phone but indicated the importance of maintaining in-person care to build relationships.

Virtual family physician care during COVID-19: a mixed methods study using health administrative data and qualitative interviews.

BACKGROUND: The onset of the COVID-19 pandemic necessitated a rapid shift in primary health care from predominantly in-person to high volumes of virtual care. The pandemic afforded the opportunity to conduct a deep regional examination of virtual care by family physicians in London and Middlesex County, Ontario, Canada that would inform the foundation for virtual care in our region post-pandemic. OBJECTIVES: (1) to determine volumes of in-person and virtual family physicians visits and characteristics of the family physicians and patients using them during the early COVID-19 pandemic; (2) to determine how virtual visit volumes changed over the pandemic, compared to in-person; and (3) to explore family physicians' experience in virtual visit adoption and implementation. METHODS: We conducted a concurrent mixed-methods study of family physicians from March to October 2020. The quantitative component examined mean weekly number of total, in-person and virtual visits using health administrative data. Differences in outcomes according to physician and practice characteristics for pandemic periods were compared to pre-pandemic. The qualitative study employed Constructivist Grounded Theory, conducting semi-structured family physicians interviews; analyzing data iteratively using constant comparative analysis. We mapped themes from the qualitative analysis to quantitative findings. RESULTS: Initial volumes of patients decreased, driven by fewer in-person visits. Virtual visit volumes increased dramatically; family physicians described using telephone almost entirely. Rural family physicians reported video connectivity issues. By early second wave, total family physician visit volume returned to pre-pandemic volumes. In-person visits increased substantially; family physicians reported this happened because previously scarce personal protective equipment became available. Patients seen during the pandemic were older, sicker, and more materially deprived. CONCLUSION: These results can inform the future of virtual family physician care including the importance of continued virtual care compensation, the need for equitable family physician payment models, and the need to attend to equity for vulnerable patients. Given the move to virtual care was primarily a move to telephone care, the modality of care delivery that is acceptable to both family physicians and their patients must be considered.

Exploring COVID-19 vaccine uptake, confidence and hesitancy among people experiencing homelessness in Toronto, Canada: protocol for the Ku-gaa-gii pimitizi-win qualitative study.

INTRODUCTION: People experiencing homelessness are at high risk for COVID-19 and poor outcomes if infected. Vaccination offers protection against serious illness, and people experiencing homelessness have been prioritised in the vaccine roll-out in Toronto, Canada. Yet, current COVID-19 vaccination rates among people experiencing homelessness are lower than the general population. This study aims to characterise reasons for COVID-19 vaccine uptake and hesitancy among people experiencing homelessness, to identify strategies to overcome hesitancy and provide public health decision-makers with information to improve vaccine confidence and uptake in this priority population. METHODS AND ANALYSIS: The Ku-gaa-gii pimitizi-win qualitative study (formerly the COVENANT study) will recruit up to 40 participants in Toronto who are identified as experiencing homelessness at the time of recruitment. Semistructured interviews with participants will explore general experiences during the COVID-19 pandemic (eg, loss of housing, social connectedness), perceptions of the COVID-19 vaccine, factors shaping vaccine uptake and strategies for supporting enablers, addressing challenges and building vaccine confidence. ETHICS AND DISSEMINATION: Approval for this study was granted by Unity Health Toronto Research Ethics Board. Findings will be communicated to groups organising vaccination efforts in shelters, community groups and the City of Toronto to construct more targeted interventions that address reasons for vaccine hesitancy among people experiencing homelessness. Key outputs will include a community report, academic publications, presentations at conferences and a Town Hall that will bring together people with lived expertise of homelessness, shelter staff, leading scholars, community experts and public health partners.

Ku-gaa-gii pimitizi-win, the COVID-19 cohort study of people experiencing homelessness in Toronto, Canada: a study protocol

Introduction Initial reports suggest people experiencing homelessness (PEH) are at high risk for SARS-CoV-2 infection and associated morbidity and mortality. However, there have been few longitudinal evaluations of the spread and impact of COVID-19 among PEH. This study will estimate the prevalence and incidence of COVID-19 infections in a cohort of PEH followed prospectively in Toronto, Canada. It will also examine associations between individual-level and shelter-level characteristics with COVID-19 infection, adverse health outcomes related to infection and vaccination. Finally, the data will be used to develop and parameterise a mathematical model to characterise SARS-CoV-2 transmission dynamics, and the transmission impact of interventions serving PEH. Design, methods and analysis Ku-gaa-gii pimitizi-win will follow a random sample of PEH from across Toronto (Canada) for 12 months. 736 participants were enrolled between June and September 2021, and will be followed up at 3-month intervals. At each interval, specimens (saliva, capillary blood) will be collected to determine active SARS-CoV-2 infection and serologic evidence of past infection and/or vaccination, and a detailed survey will gather self-reported information, including a detailed housing history. To examine the association between individual-level and shelter-level characteristics on COVID-19-related infection, adverse outcomes, and vaccination, shelter and healthcare administrative data will be linked to participant study data. Healthcare administrative data will also be used to examine long-term (up to 5 years) COVID-19-related outcomes among participants. Ethics and dissemination Ethical approval was obtained from the Unity Health Toronto and University of Toronto Health Sciences Research Ethics Boards (# 20-272). Ku-gaa-gii pimitizi-win was designed in collaboration with community and service provider partners and people having lived experience of homelessness. Findings will be reported to groups supporting Ku-gaa-gii pimitizi-win, Indigenous and other community partners and service providers, funding bodies, public health agencies and all levels of government to inform policy and public health programs.

COVID-19 Vaccine Coverage and Sociodemographic, Behavioural and Housing Factors Associated with Vaccination among People Experiencing Homelessness in Toronto, Canada: A Cross-Sectional Study.

People experiencing homelessness were prioritized for COVID-19 vaccination in Toronto, Canada, due to the high risk of infection and associated complications relative to the general population. We aimed to ascertain COVID-19 vaccine coverage in this population and explore factors associated with the receipt of at least one dose. We collected survey and blood sample data from individuals ages 16+ recruited by random selection at 62 shelters, hotels and encampment sites between 16 June 2021 and 9 September 2021. We report vaccine coverage by dose number and explored sociodemographic, behavioral, health and housing factors associated with vaccination using multivariable modified Poisson regression. In total, 80.4% (95% CI 77.3-83.1%) received at least one vaccine dose, and 63.6% (CI 60.0-67.0%) received two or more doses. Vaccination was positively associated with age (every 10 years adjusted rate ratio (aRR) 1.05 [95% CI 1.03-1.08]), and receipt of influenza vaccination (aRR 1.19 [95% CI 1.11-1.27]). Factors negatively associated with vaccination included female gender (aRR 0.92 [95% CI 0.85-1.0]), Black racial self-identification (aRR 0.89 [95% CI 0.80-0.99]) and low frequencies of masking in public places (aRR 0.83 [95% CI 0.72-0.95]). COVID-19 vaccine coverage is very high among people experiencing homelessness in Toronto, suggesting advocacy and outreach efforts may have been effective.

Hospitalizations During the COVID-19 Pandemic Among Recently Homeless Individuals: a Retrospective Population-Based Matched Cohort Study.

BACKGROUND: Hospitalizations fell precipitously among the general population during the COVID-19 pandemic. It remains unclear whether individuals experiencing homelessness experienced similar reductions. OBJECTIVE: To examine how overall and cause-specific hospitalizations changed among individuals with a recent history of homelessness (IRHH) and their housed counterparts during the first wave of the COVID-19 pandemic, using corresponding weeks in 2019 as a historical control. DESIGN: Population-based cohort study conducted in Ontario, Canada, between September 30, 2018, and September 26, 2020. PARTICIPANTS: In total, 38,617 IRHH, 15,022,368 housed individuals, and 186,858 low-income housed individuals matched on age, sex, rurality, and comorbidity burden. MAIN MEASURES: Primary outcomes included medical-surgical, non-elective (overall and cause-specific), elective surgical, and psychiatric hospital admissions. KEY RESULTS: Average rates of medical-surgical (rate ratio: 3.8, 95% CI: 3.7-3.8), non-elective (10.3, 95% CI: 10.1-10.4), and psychiatric admissions (128.1, 95% CI: 126.1-130.1) between January and September 2020 were substantially higher among IRHH compared to housed individuals. During the peak period (March 17 to June 16, 2020), rates of medical-surgical (0.47, 95% CI: 0.47-0.47), non-elective (0.80, 95% CI: 0.79-0.80), and psychiatric admissions (0.86, 95% CI: 0.84-0.88) were significantly lower among housed individuals relative to equivalent weeks in 2019. No significant changes were observed among IRHH. During the re-opening period (June 17-September 26, 2020), rates of non-elective hospitalizations for liver disease (1.41, 95% CI: 1.23-1.69), kidney disease (1.29, 95% CI: 1.14-1.47), and trauma (1.19, 95% CI: 1.07-1.32) increased substantially among IRHH but not housed individuals. Distinct hospitalization patterns were observed among IRHH even in comparison with more medically and socially vulnerable matched housed individuals. CONCLUSIONS: Persistence in overall hospital admissions and increases in non-elective hospitalizations for liver disease, kidney disease, and trauma indicate that the COVID-19 pandemic presented unique challenges for recently homeless individuals. Health systems must better address the needs of this population during public health crises.

COVID-19 vaccine coverage and factors associated with vaccine uptake among 23 247 adults with a recent history of homelessness in Ontario, Canada: a population-based cohort study.

BACKGROUND: People experiencing homelessness face a high risk of SARS-CoV-2 infection and transmission, as well as health complications and death due to COVID-19. Despite being prioritised for receiving the COVID-19 vaccine in many regions, little data are available on vaccine uptake in this vulnerable population. Using population-based health-care administrative data from Ontario, Canada-a region with a universal, publicly funded health system-we aimed to describe COVID-19 vaccine coverage (ie, the estimated percentage of people who have received a vaccine) and determinants of vaccine receipt among individuals with a recent history of homelessness. METHODS: We conducted a retrospective, population-based cohort study of adults (aged ≥18 years) with a recent experience of homelessness, inadequate housing, or shelter use as recorded in routinely collected health-care databases between June 14, 2020, and June 14, 2021 (a period within 6 months of Dec 14, 2020, when COVID-19 vaccine administration was initiated in Ontario). Participants were followed up from Dec 14, 2020, to Sept 30, 2021, for the receipt of one or two doses of a COVID-19 vaccine using the province's real-time centralised vaccine information system. We described COVID-19 vaccine coverage overall and within predefined subgroups. Using modified Poisson regression, we further identified sociodemographic factors, health-care usage, and clinical factors associated with receipt of at least one dose of a COVID-19 vaccine. FINDINGS: 23 247 individuals with a recent history of homelessness were included in this study. Participants were predominantly male (14 752 [63·5%] of 23 247); nearly half were younger than 40 years (11 521 [49·6%]) and lived in large metropolitan regions (12 123 [52·2%]); and the majority (18 226 [78·4%]) visited a general practitioner for an in-person consultation during the observation period. By Sept 30, 2021, 14 271 (61·4%; 95% CI 60·8-62·0) individuals with a recent history of homelessness had received at least one dose of a COVID-19 vaccine and 11 082 (47·7%; 47·0-48·3) had received two doses; in comparison, over the same period, 86·6% of adults in the total Ontario population had received a first dose and 81·6% had received a second dose. In multivariable analysis, factors positively associated with COVID-19 uptake were one or more outpatient visits to a general practitioner (adjusted risk ratio [aRR] 1·37 [95% CI 1·31-1·42]), older age (50-59 years vs 18-29 years: 1·18 [1·14-1·22], ≥60 years vs 18-29 years: 1·27 [1·22-1·31]), receipt of an influenza vaccine in either of the two previous influenza seasons (1·25 [1·23-1·28]), being identified as homeless via a visit to a community health centre versus exclusively a hospital-based encounter (1·13 [1·10-1·15]), receipt of one or more SARS-CoV-2 tests between March 1, 2020, and Sept 30, 2021 (1·23 [1·20-1·26]), and the presence of chronic health conditions (one condition: 1·05 [1·03-1·08]; two or more conditions: 1·11 [1·08-1·14]). By contrast, living in a smaller metropolitan region (aRR 0·92 [95% CI 0·90-0·94]) or rural location (0·93 [0·90-0·97]) versus large metropolitan regions were associated with lower uptake. INTERPRETATION: In Ontario, COVID-19 vaccine coverage among adults with a recent history of homelessness has lagged and, as of Sept 30, 2021, was 25 percentage points lower than that of the general adult population in Ontario for a first dose and 34 percentage points lower for a second dose. With high usage of outpatient health services among individuals with a recent history of homelessness, better utilisation of outpatient primary care structures might offer an opportunity to increase vaccine coverage in this population. Our findings underscore the importance of leveraging existing health and service organisations that are accessed and trusted by people who experience homelessness for targeted vaccine delivery. FUNDING: The Public Health Agency of Canada. TRANSLATION: For the French translation of the abstract see Supplementary Materials section.

Association between Pet Ownership and Mental Health and Well-Being of Canadians Assessed in a Cross-Sectional Study during the COVID-19 Pandemic.

The objective of this cross-sectional study was to assess the association between pet ownership and quality of life (QoL), loneliness, anxiety, stress, overall health, and mental health of Canadians during the COVID-19 pandemic using a One Health perspective. An online bilingual survey was completed by 1500 Canadians in April-May 2021. Socio-demographics, health, QoL, stress and anxiety, loneliness, social support, pet ownership, and attitude towards pets data were collected. Crude and adjusted associations between pet ownership and mental health and well-being indicators were estimated. The 1500 participants were from all provinces and territories, half were women; half of the participants were pet owners by design. The crude association estimates showed that pet owners had poorer QoL, overall health, and mental health than non-pet owners, and were lonelier, more stressed, and more anxious than non-pet owners. Adjusted estimates showed that these associations disappeared with the inclusion of the confounders (socio-economic, demographic, health, and pet-related variables). Our results suggest that there was no association between pet ownership and the mental health and well-being indicators measured in the present study.

Drug Overdoses During the COVID-19 Pandemic Among Recently Homeless Individuals.

AIMS: To examine how weekly rates of emergency department (ED) visits for drug overdoses changed among individuals with a recent history of homelessness (IRHH) and their housed counterparts during the pre-pandemic, peak, and re-opening periods of the first wave of the COVID-19 pandemic, using corresponding weeks in 2019 as a historical control. DESIGN: Population-based retrospective cohort study conducted between September 30, 2018 and September 26, 2020. SETTING: Ontario, Canada. PARTICIPANTS: A total of 38 617 IRHH, 15 022 369 housed individuals, and 186 858 low-income housed individuals matched on age, sex, rurality, and comorbidity burden. MEASUREMENTS: ED visits for drug overdoses of accidental and undetermined intent. FINDINGS: Average rates of ED visits for drug overdoses between January and September 2020 were higher among IRHH compared with housed individuals (rate ratio [RR], 148.0; 95% CI, 142.7-153.5) and matched housed individuals (RR, 22.3; 95% CI, 20.7-24.0). ED visits for drug overdoses decreased across all groups by ~20% during the peak period (March 17 to June 16, 2020) compared with corresponding weeks in 2019. During the re-opening period (June 17 to September 26, 2020), rates of ED visits for drug overdoses were significantly higher among IRHH (RR, 1.56; 95% CI, 1.44-1.69), matched housed individuals (RR, 1.25; 95% CI, 1.08-1.46), and housed individuals relative to equivalent weeks in 2019 (RR, 1.07; 95% CI, 1.02-1.11). The relative increase in drug overdose ED visits among IRHH was larger compared with both matched housed individuals (P = 0.01 for interaction between group and year) and housed individuals (P < 0.001) during this period. CONCLUSIONS: Recently homeless individuals in Ontario, Canada experienced disproportionate increases in ED visits for drug overdoses during the re-opening period of the COVID-19 pandemic compared with housed people.

Is coronavirus disease 2019 associated with indicators of long-term bladder dysfunction?

OBJECTIVE: Early reports have suggested that coronavirus disease 2019 (COVID-19) can present with significant urinary frequency and nocturia, and that these symptoms correlate with markers of inflammation in the urine. We evaluated surrogate markers of chronic urinary symptoms to determine if they were more frequent after COVID-19 infection. METHODS: Routinely collected data from the province of Ontario was used to conduct a matched, retrospective cohort study. We identified patients 66 years of age or older who had a positive COVID-19 test between February and May 2020 and survived at least 2 months after their diagnosis. We matched them to two similar patients who did not have a positive COVID-19 test during the same time period. We measured the frequency of urology consultation, cystoscopy, and new prescriptions for overactive bladder medications during a subsequent 3-month period. Proportional hazard models were adjusted for any baseline differences between the groups. RESULTS: We matched 5617 patients with COVID-19 to 11,225 people who did not have COVID-19. The groups were similar, aside from a higher proportion of patients having hypertension and diabetes in the CoVID-19 cohort. There was no significantly increased hazard of new receipt of overactive bladder medication (hazards ratio [HR]: 1.04, p = 0.88), urology consultation (HR: 1.40, p = 0.10), or cystoscopy (HR: 1.14, p = 0.50) among patients who had COVID-19, compared to the matched cohort. CONCLUSION: Surrogate markers of potential bladder dysfunction were not significantly increased in the 2-5 months after COVID-19 infection.

Were Snowbirds Disproportionally Impacted by COVID-19? An Ontario Analysis.

Early in the first wave of the COVID-19 pandemic, many older adult Canadians who routinely spend the winter months in warmer regions (colloquially known as "snowbirds") returned to Canada. While numerous infections were attributed to travel-related exposure at that time, little is known about the impact of COVID-19 on returning snowbirds. This population-based analysis from Ontario suggests that snowbirds were not disproportionately impacted by the pandemic. However, as older adults, they remain at high risk of complications once infected. These findings underscore the need for continued caution in this older adult population.

Testing, infection and complication rates of COVID-19 among people with a recent history of homelessness in Ontario, Canada: a retrospective cohort study.

BACKGROUND: People with a recent history of homelessness are believed to be at high risk of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and, when infected, complications of coronavirus disease 2019 (COVID-19). We describe and compare testing for SARS-CoV-2, test positivity and hospital admission, receipt of intensive care and mortality rates related to COVID-19 for people with a recent history of homelessness versus community-dwelling people as of July 31, 2020. METHODS: We conducted a population-based retrospective cohort study in Ontario, Canada, between Jan. 23 and July 31, 2020, using linked health administrative data among people who either had a recent history of homelessness or were dwelling in the community. People were included if they were eligible for provincial health care coverage and not living in an institutionalized facility on Jan. 23, 2020. We examined testing for SARS-CoV-2, test positivity and complication outcomes of COVID-19 (hospital admission, admission to intensive care and death) within 21 days of a positive test result. Extended multivariable Cox proportional hazard models were used to estimate adjusted hazard ratios (HRs) in 3 time periods: preshutdown (Jan. 23-Mar. 13), peak (Mar. 14-June 16) and reopening (June 17-July 31). RESULTS: People with a recent history of homelessness (n = 29 407) were more likely to be tested for SARS-CoV-2 in all 3 periods compared with community-dwelling people (n = 14 494 301) (preshutdown adjusted HR 1.61, 95% confidence interval [CI] 1.22-2.11; peak adjusted HR 2.95, 95% CI 2.88-3.03; reopening adjusted HR 1.45, 95% CI 1.39-1.51). They were also more likely to have a positive test result (peak adjusted HR 3.66, 95% CI 3.22-4.16; reopening adjusted HR 1.76, 95% CI 1.15-2.71). In the peak period, people with a recent history of homelessness were over 20 times more likely to be admitted to hospital for COVID-19 (adjusted HR 20.35, 95% CI 16.23-25.53), over 10 times more likely to require intensive care for COVID-19 (adjusted HR 10.20, 95% CI 5.81-17.93) and over 5 times more likely to die within 21 days of their first positive test result (adjusted HR 5.73, 95% CI 3.01-10.91). INTERPRETATION: In Ontario, people with a recent history of homelessness were significantly more likely to be tested for SARS-CoV-2, to have a positive test result, to be admitted to hospital for COVID-19, to receive intensive care for COVID-19 and to die of COVID-19 compared with community-dwelling people. People with a recent history of homelessness should continue to be considered particularly vulnerable to SARS-CoV-2 infection and its complications.