Vaccination against SARS-CoV-2 infection among vulnerable and marginalised population groups in Denmark: A nationwide population-based study

A conceptual framework to model social determinants of COVID-19 vaccination uptake among underserved homeless populations

Background

 Homeless people have a higher risk of COVID-19 infection, linked to several social, economic and environmental determinants, frequent comorbidities, obstacles to exercising their constitutional social and health rights, poor medical cover, and insufficient use of the healthcare system. Data on COVID-19 vaccine uptake and its main determinants are lacking for this underserved population.

Objectives

 To construct and test a conceptual framework to model structural social determinants of COVID-19 vaccine uptake among underserved homeless populations, and to test this model to identify the determinants of COVID-19 vaccine uptake on the homeless population living in two metropolitan areas in France.

Methods

 We implemented a multicenter cross-sectional survey from 15/11/2021 to 22/12/2021 in homeless adults in the city of Marseille and in the greater Paris area. Persons sheltered in migrant worker hostels or in emergency social shelters, members of the COVID HOMELESS cohort study in Marseille, and Travelers living in traditional housing were all eligible. A standardized face-to-face questionnaire was administered to the participants where they lived in various languages by trained interviewers. We used structural equation modeling to analyze the structural social determinants of COVID-19 vaccine uptake, the latter defined as receiving at least one dose.

Results

 The participation rate was 64 %, accounting for 3811 participants. There were three main factors associated with greater vaccine uptake: i) opportunity, which included having a personal general practitioner (β = 0.05, p < 0.05), healthcare cover (β = 0.05, p < 0.05), and somebody to accompany the participant for medical appointments (β = -0.04, p < 0.05); ii) motivation, which included attitudes towards vaccination (β = 0.55, p < 0.05), press- and poster-based information (β = 0.03, p < 0.05), and vaccination history (β = 0.03, p < 0.05); iii) type of housing (β = 0.13, p < 0.05) and housing stability (β = 0.04, p < 0.05).

Conclusion

 Our results highlight that housing exclusion is a structural social determinant of COVID-19 vaccine uptake in homeless people in France. They also underline the role which opportunity and motivation play in improving uptake in this underserved homeless population.

Effects of the COVID-19 pandemic on people experiencing incarceration: a systematic review

OBJECTIVE

To assess the effect of the COVID-19 pandemic on people experiencing incarceration (PEI), focusing particularly on clinical outcomes compared with the general population.

DESIGN

Systematic review with narrative synthesis in accordance with the Centre for Reviews and Dissemination's good practice guidelines.

DATA SOURCES

Medline, Social Policy and Practice, Criminology Connection, ASSIA, EMBASE, SCOPUS, Web Of Science, CINAHL, Cochrane Library, Cochrane COVID-19 reviews, COVID-19 Evidence Reviews and L*OVE COVID-19 Evidence databases were searched up to 21 October 2022.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

We included studies presenting data specific to adults ≥18 years experiencing incarceration, with exposure to SARS-CoV-2 infection. All studies with a comparison group, regardless of study design and country were included. Studies with no comparison group data or not measuring clinical outcomes/health inequalities were excluded. Studies focussing on detained migrants, forensic hospitals, prison staff and those not in English were also excluded.

DATA EXTRACTION AND SYNTHESIS

Two reviewers extracted data and assessed risk of bias. Data underwent narrative synthesis using a framework analysis based on the objectives, for infection rates, testing, hospitalisation, mortality, vaccine uptake rates and mental health outcomes. There was no scope for meta-analysis, due to the heterogeneity of evidence available.

RESULTS

4516 references were exported from the databases and grey literature searched, of which 55 met the inclusion criteria. Most were from the USA and were retrospective analyses. Compared with the general population, PEI were usually found to have higher rates of SARS-CoV-2 infection and poorer clinical outcomes. Conflicting data were found regarding vaccine uptake and testing rates compared with the general population. The mental health of PEI declined during the pandemic. Certain subgroups were more adversely affected by the COVID-19 pandemic, such as ethnic minorities and older PEI.

CONCLUSION

PEI have poorer COVID-19 clinical outcomes than the general public, as shown by largely low-quality heterogenous evidence. Further high-quality research of continuing clinical outcomes and appropriate mitigating interventions is required to assess downstream effects of the pandemic on PEI. However, performing such research in the context of incarceration facilities is highly complex and potentially challenging. Prioritisation of resources for this vulnerable group should be a focus of national policy in the event of future pandemics.

PROSPERO REGISTRATION NUMBER

CRD42022296968.

Sociodemographic disparities affect COVID-19 vaccine uptake in non-elderly adults with increased risk of severe COVID-19

BACKGROUND

There is limited information about sociodemographic disparities in COVID-19 vaccine uptake among non-elderly adults with an increased risk of severe COVID-19. We investigated the COVID-19 vaccine uptake in individuals aged 18-64 years with an increased risk of severe COVID-19 (non-elderly risk group) in Stockholm County, Sweden.

METHOD

We used population-based health and sociodemographic registries with high coverage to perform a cohort study of COVID-19 vaccine uptake of one to four doses up until 21 November 2022. The vaccine uptake in the non-elderly risk group was compared with non-risk groups aged 18-64 years (non-elderly non-risk group) and individuals aged ≥65 years (elderly).

RESULTS

The uptake of ≥3 vaccine doses was 55%, 64% and 87% in the non-elderly non-risk group (n = 1,005,182), non-elderly risk group (n = 308,904) and elderly (n = 422,604), respectively. Among non-elderly risk group conditions, Down syndrome showed the strongest positive association with receiving three doses (adjusted risk ratio [aRR] 1.62, 95% confidence interval [CI] 1.54-1.71), whereas chronic liver disease showed the strongest negative association (aRR 0.90, 95% CI 0.88-0.92). Higher vaccine uptake among the non-elderly risk group was associated with increasing age, being born in Sweden, higher education, higher income and living in a household where other adults had been vaccinated. Similar trends were observed for the first, second, third and fourth doses.

CONCLUSION

These results call for measures to tackle sociodemographic disparities in vaccination programmes during and beyond the COVID-19 pandemic.

Risk factors for poor COVID-19 outcomes in patients with psychiatric disorders

BACKGROUND

Coronavirus disease 2019 (COVID-19) has been found to have a greater impact on individuals with pre-existing psychiatric disorders. However, the underlying reasons for this increased risk have yet to be determined. This study aims to investigate the potential factors contributing poor outcomes among COVID-19 patients with psychiatric disorders, including delayed diagnosis of infection, vaccination rates, immune response, and the use of psychotropic medications.

METHODS

This retrospective cohort study analyzed medical records of 15,783 adult patients who were diagnosed with COVID-19 infection by positive PCR tests between January and September 2022 at a single medical center. We identified psychiatric diagnoses using ICD-9 diagnostic codes from the preceding 3 years before COVID infection. Primary outcome was in-hospital mortality and secondary outcomes were severe illness requiring intensive care or mechanical ventilation, and hospitalization within 45 days after a positive COVID-19 test. We compared the rates of outcomes, viral load, vaccination status at the time of positive test, psychotropic medications prescription within 90 days prior, antiviral medication use, and blood inflammation markers between patients with and without psychiatric disorders. The Cox proportional hazard model was used to examine the association of psychiatric diagnoses, vaccination status, and psychotropic medication prescription with poor outcomes.

RESULTS

Patients with psychiatric disorders demonstrated higher rates of severe illness (10.4% v.s. 7.1%) and hospitalization (16.4% vs. 11.3%), as well as a shorter duration to in-hospital mortality (6 vs. 12.5 days) compared to non-psychiatric patients. Psychiatric patients had higher vaccination rates and lower levels of inflammatory markers than non-psychiatric patients. Antipsychotic medication use was associated with in-hospital mortality (hazard ratio [HR] = 4.79, 95% confidence interval [CI] = 1.23-18.7), while being unvaccinated was associated with hospitalization (HR = 1.81, 95% CI = 1.29 to 2.54) and severe illness (HR = 3.23, 95% CI = 1.95 to 5.34) among patients with psychiatric disorders. Sedatives prescription was associated with all poor outcomes in general patients.

CONCLUSION

Considering the narrow time window between a positive COVID-19 test and poor outcomes, healthcare providers should undertake close monitoring of patients with preexisting psychiatric disorders during the initial days after a positive PCR test. Furthermore, caution should be taken when prescribing psychotropic medications, with special attention to antipsychotics.

SARS-CoV-2 incidence, seroprevalence, and COVID-19 vaccination coverage in the homeless population: a systematic review and meta-analysis

Objectives

SARS-CoV-2 infection and COVID-19 vaccination of homeless people are a serious public health concern during COVID-19 pandemic. We aimed to systematically assess SARS-CoV-2 incidence, seroprevalence, and COVID-19 vaccination coverage in homeless people, which are important to inform resource allocation and policy adjustment for the prevention and control of COVID-19.

Methods

We searched PubMed, Web of Science, and the World Health Organization COVID-19 database for the studies of SARS-CoV-2 incidence, seroprevalence, and COVID-19 vaccination coverage in the homeless population. Subgroup analyses were conducted to pool SARS-CoV-2 incidence and seroprevalence in sheltered homeless, unsheltered homeless, and mixed population, respectively. Potential sources of heterogeneity in the estimates were explored by meta-regression analysis.

Results

Forty-nine eligible studies with a total of 75,402 homeless individuals and 5,000 shelter staff were included in the meta-analysis. The pooled incidence of SARS-CoV-2 infection was 10% (95% CI: 7 to 12%) in the homeless population and 8% (5 to 12%) for shelter staff. In addition, the overall estimated SARS-CoV-2 specific seroprevalence was 19% (8 to 33%) for homeless populations and 22% (3 to 52%) for shelter staff, respectively. Moreover, for the homeless subjects, the pooled incidence was 10% (4 to 23%) for asymptomatic SARS-CoV-2 infections, 6% (1 to 12%) for symptomatic SARS-CoV-2 infections, 3% (1 to 4%) for hospitalization for COVID-19, and 1% (0 to 2%) for severe COVID-19 cases, respectively while no COVID-19-related death was reported. Furthermore, the data derived from 12 included studies involving 225,448 homeless individuals revealed that the pooled proportion of one dose COVID-19 vaccination was 41% (35 to 47%), which was significantly lower than those in the general population.

Conclusion

Our study results indicate that the homeless people remain highly susceptible to SARS-CoV-2 infection, but COVID-19 vaccination coverage was lower than the general population, underscoring the need for prioritizing vaccine deployment and implementing enhanced preventive measures targeting this vulnerable group.

The Impact of Being Homeless on the Clinical Outcomes of COVID-19: Systematic Review

Objective: The homeless population experiences inequality in health compared with the general population, which may have widened during the COVID-19 pandemic. However, the impact of being homeless on the outcomes of COVID-19 is uncertain. This systematic review aimed to analyse the impact of experiencing homelessness on the clinical outcomes of COVID-19, including the effects on health inequalities. Methods: A review protocol was developed and registered in PROSPERO (PROSPERO registration 2022 CRD42022304941). Nine databases were searched in November 2022 to identify studies on homeless populations which contained primary research on the following outcomes of COVID-19: incidence, hospitalisation, mortality, long COVID, mental wellbeing, and evidence of inequalities. Included studies were summarised with narrative synthesis. Results: The searches yielded 8,233 initial hits; after screening, 41 studies were included. Overall, evidence showed that those in crowded living settings had a higher risk of COVID-19 infection compared to rough sleepers and the general population. The homeless population had higher rates of hospitalisation and mortality than the general population, lower vaccination rates, and suffered negative mental health impacts. Conclusion: This systematic review shows the homeless population is more susceptible to COVID-19 outcomes. Further research is needed to determine the actual impact of the pandemic on this population, and of interventions to mitigate overall risk, given the low certainty of findings from some of the low-quality evidence available. In addition, further research is required to ascertain the impact of long COVID on those experiencing homelessness, since the present review yielded no studies on this topic.

Patterns of testing in the extensive Danish national SARS-CoV-2 test set-up

BACKGROUND

The Danish national SARS-CoV-2 mass test system was among the most ambitious worldwide. We describe its set-up and analyse differences in patterns of testing per demography and time period in relation to the three waves of SARS-CoV-2 transmission in Denmark.

METHODS

We included all reported PCR- and rapid antigen-tests performed between 27 February 2020 and 10 March 2022 among all residents aged 2 years or above. Descriptive statistics and Poisson regression models were used to analyse characteristics of individuals tested for SARS-CoV-2 using a national cohort study design.

RESULTS

A total of 63.7 million PCR-tests and 60.0 million rapid antigen-tests were performed in the study period, testing 90.9% and 78.8% of the Danish population at least once by PCR or antigen, respectively. Female sex, younger age, Danish heritage and living in the capital area were all factors positively associated with the frequency of PCR-testing. The association between COVID-19 vaccination and PCR-testing changed from negative to positive over time.

CONCLUSION

We provide details of the widely available, free-of-charge, national SARS-CoV-2 test system, which served to identify infected individuals, assist isolation of infectious individuals and contact tracing, and thereby mitigating the spread of SARS-CoV-2 in the Danish population. The test system was utilized by nearly the entire population at least once, and widely accepted across different demographic groups. However, demographic differences in the test uptake did exist and should be considered in order not to cause biases in studies related to SARS-CoV-2, e.g., studies of transmission and vaccine effectiveness.

[COVID-19 vaccination for people with severe mental diseases : Results of the COVID Ψ outpatient survey and recommendations for psychiatry]

BACKGROUND

Severe mental illnesses are risk factors for SARS-CoV-2-related morbidity and mortality. Vaccination is an effective protection; therefore, high vaccination rates should be a major priority for people with mental illnesses.

OBJECTIVES

(1) Identification of at-risk groups for non-vaccination and structures and interventions needed for widespread vaccination among people with mental illnesses from the perspective of outpatient psychiatrists and neurologists, (2) discussion of the results in the context of the international literature and (3) recommendations derived from them.

MATERIAL AND METHODS

Qualitative content analysis of COVID-19 vaccination-related questions from the COVID Ψ online survey of n = 85 psychiatrists and neurologists in Germany.

RESULTS

In the survey, people with schizophrenia, severe lack of drive, low socioeconomic status and homelessness were seen as risk groups for non-vaccination. Increased and targeted information, education, addressing and motivation and easily accessible vaccination offers by general practitioners, psychiatrists, and neurologists as well as complementary institutions were considered as important interventions.

DISCUSSION

COVID-19 vaccinations as well as information, motivation and access support should be systematically offered by as many institutions of the psychiatric, psychotherapeutic and complementary care systems in Germany as possible.

Association between SARS-CoV-2 infection and self-harm: Danish nationwide register-based cohort study

BACKGROUND

Case studies have linked SARS-CoV-2 infection to suicidal behaviour. However, conclusive evidence is lacking.

AIMS

To examine whether a history of SARS-CoV-2 infection or SARS-CoV-2-related hospital admission was associated with self-harm in the general population and in high-risk groups.

METHOD

A cohort design was applied to nationwide data on all people aged ≥15 years and living in Denmark between 27 February 2020 and 15 October 2021. Exposure was identified as having had a positive SARS-CoV-2 PCR test, and further assessed as SARS-CoV-2-related hospital admission. Rates of probable self-harm were examined using adjusted incidence rate ratios (aIRRs). The following subgroups were identified: (a) lower educational level, (b) chronic medical conditions, (c) disability pension, (d) mental disorders, (e) substance use disorders, and history of (f) homelessness and (g) imprisonment.

RESULTS

Among 4 412 248 included individuals, 260 663 (5.9%) had tested positive for SARS-CoV-2. Out of 5453 individuals presenting with self-harm, 131 (2.4%) had been infected. Individuals with a history of a positive SARS-CoV-2 test result had an aIRR for self-harm of 0.86 (95% CI 0.72-1.03) compared with those without. High rates were found after a SARS-CoV-2-related hospital admission (aIRR = 7.68; 95% CI 5.61-10.51) or a non-SARS-CoV-2-related admission (aIRR = 10.27; 95% CI 9.65-10.93) versus non-infected and not admitted. In sensitivity analyses with a more restrictive definition of self-harm, a positive PCR test was associated with lower rates of self-harm.

CONCLUSIONS

Individuals with a PCR-confirmed SARS-CoV-2 infection did not have higher rates of self-harm than those without. Hospital admission in general, rather than being SARS-CoV-2 positive. seemed to be linked to elevated rates of self-harm.

Risk of SARS-CoV-2 infection, severe COVID-19 illness and COVID-19 mortality in people with pre-existing mental disorders: an umbrella review

INTRODUCTION

The COVID-19 pandemic has posed a serious health risk, especially in vulnerable populations. Even before the pandemic, people with mental disorders had worse physical health outcomes compared to the general population. This umbrella review investigated whether having a pre-pandemic mental disorder was associated with worse physical health outcomes due to the COVID-19 pandemic.

METHODS

Following a pre-registered protocol available on the Open Science Framework platform, we searched Ovid MEDLINE All, Embase (Ovid), PsycINFO (Ovid), CINAHL, and Web of Science up to the 6th of October 2021 for systematic reviews on the impact of COVID-19 on people with pre-existing mental disorders. The following outcomes were considered: risk of contracting the SARS-CoV-2 infection, risk of severe illness, COVID-19 related mortality risk, risk of long-term physical symptoms after COVID-19. For meta-analyses, we considered adjusted odds ratio (OR) as effect size measure. Screening, data extraction and quality assessment with the AMSTAR 2 tool have been done in parallel and duplicate.

RESULTS

We included five meta-analyses and four narrative reviews. The meta-analyses reported that people with any mental disorder had an increased risk of SARS-CoV-2 infection (OR: 1.71, 95% CI 1.09-2.69), severe illness course (OR from 1.32 to 1.77, 95%CI between 1.19-1.46 and 1.29-2.42, respectively) and COVID-19 related mortality (OR from 1.38 to 1.52, 95%CI between 1.15-1.65 and 1.20-1.93, respectively) as compared to the general population. People with anxiety disorders had an increased risk of SAR-CoV-2 infection, but not increased mortality. People with mood and schizophrenia spectrum disorders had an increased COVID-19 related mortality but without evidence of increased risk of severe COVID-19 illness. Narrative reviews were consistent with findings from the meta-analyses.

DISCUSSION AND CONCLUSIONS

As compared to the general population, there is strong evidence showing that people with pre-existing mental disorders suffered from worse physical health outcomes due to the COVID-19 pandemic and may therefore be considered a risk group similar to people with underlying physical conditions. Factors likely involved include living accommodations with barriers to social distancing, cardiovascular comorbidities, psychotropic medications and difficulties in accessing high-intensity medical care.

Estimating COVID-19 vaccine uptake and its drivers among migrants, homeless and precariously housed people in France

BACKGROUND

Migrants, people experiencing homelessness (PEH), or precariously housed (PH) are at high risk for COVID-19 infection, hospitalization, and death from COVID-19. However, while data on COVID-19 vaccine uptake in these populations are available in the USA, Canada, and Denmark, we are lacking, to the best of our knowledge, data from France.

METHODS

In late 2021, we carried out a cross-sectional survey to determine COVID-19 vaccine coverage in PEH/PH residing in Ile-de-France and Marseille, France, and to explore its drivers. Participants aged over 18 years were interviewed face-to-face where they slept the previous night, in their preferred language, and then stratified for analysis into three housing groups (Streets, Accommodated, and Precariously Housed). Standardized vaccination rates were computed and compared to the French population. Multilevel univariate and multivariable logistic regression models were built.

RESULTS

We find that 76.2% (95% confidence interval [CI] 74.3-78.1) of the 3690 participants received at least one COVID-19 vaccine dose while 91.1% of the French population did so. Vaccine uptake varies by stratum, with the highest uptake (85.6%; reference) in PH, followed by Accommodated (75.4%; adjusted odds-ratio = 0.79; 95% CI 0.51-1.09 vs. PH) and lowest in Streets (42.0%; AOR = 0.38; 95%CI 0.25-0.57 vs. PH). Use for vaccine certificate, age, socioeconomic factors, and vaccine hesitancy is associated with vaccination coverage.

CONCLUSIONS

In France, PEH/PH, and especially the most excluded, are less likely than the general population to receive COVID-19 vaccines. While vaccine mandate has proved an effective strategy, targeted outreach, on-site vaccinations, and sensitization activities are strategies enhancing vaccine uptake that can easily be replicated in future campaigns and other settings.

COVID-19 Vaccination among a Population Experiencing Homelessness: A Survey in Italy

The purposes of this cross-sectional study were to determine the knowledge, attitudes, and behaviors about COVID-19 and its vaccination among 313 individuals experiencing homelessness in Italy and to identify the associated factors. A total of 20.5% identified the virus as a causative agent for COVID-19 and 44.2% identified how the SARS-CoV-2 infection wastransmitted. Those living in homeless shelters were more likely to have this knowledge. Concerns about the safety of the COVID-19 vaccine werehigher in those who were younger, with secondary school as the highest level of education, who practiced Christianity, and who did not believe that COVID-19 was a severe disease. A total of 83.9% received the vaccination. Those who were older, who had correct knowledge, whoperceived to be at a higher risk of getting the disease, and who had a lower concern about the vaccine side effects were more likely to have received the vaccination. The primary reasons for accepting the COVID-19 vaccine were that it wasa preventive measure and that it wasmandatory; those unvaccinated indicated, as the main reasons, a fear of side effects and that it wasnot useful. A relationship and communication between healthcare professionals and this hard-to-reach population are needed, with the implementation of educational and information programs.

Changes in Social and Clinical Determinants of COVID-19 Outcomes Achieved by the Vaccination Program: A Nationwide Cohort Study

BACKGROUND

The objective of this study was to assess changes in social and clinical determinants of COVID-19 outcomes associated with the first year of COVID-19 vaccination rollout in the Basque population.

METHODS

A retrospective study was performed using the complete database of the Basque Health Service (n = 2,343,858). We analyzed data on age, sex, socioeconomic status, the Charlson comorbidity index (CCI), hospitalization and intensive care unit (ICU) admission, and COVID-19 infection by Cox regression models and Kaplan-Meier curves.

RESULTS

Women had a higher hazard ratio (HR) of infection (1.1) and a much lower rate of hospitalization (0.7). With older age, the risk of infection fell, but the risks of hospitalization and ICU admission increased. The higher the CCI, the higher the risks of infection and hospitalization. The risk of infection was higher in high-income individuals in all periods (HR = 1.2-1.4) while their risk of hospitalization was lower in the post-vaccination period (HR = 0.451).

CONCLUSION

Despite the lifting of many control measures during the second half of 2021, restoring human mobility patterns, the situation could not be defined as syndemic, clinical determinants seeming to have more influence than social ones on COVID-19 outcomes, both before and after vaccination program implementation.

Adverse SARS-CoV-2-associated outcomes among people experiencing social marginalisation and psychiatric vulnerability: A population-based cohort study among 4,4 million people

Background

Knowledge of the adverse problems related to SARS-CoV-2 infection in marginalised and deprived groups may help to prioritise more preventive efforts in these groups. We examined adverse outcomes associated with SARS-CoV-2 infection among vulnerable segments of society.

Methods

Using health and administrative registers, a population-based cohort study of 4.4 million Danes aged at least 15 years from 27 February 2020 to 15 October 2021 was performed. People with 1) low educational level, 2) homelessness, 3) imprisonment, 4) substance abuse, 5) supported psychiatric housing, 6) psychiatric admission, and 7) severe mental illness were main exposure groups. Chronic medical conditions were included for comparison. COVID-19-related outcomes were: 1) hospitalisation, 2) intensive care, 3) 60-day mortality, and 4) overall mortality. PCR-confirmed SARS-CoV-2 infection and PCR-testing were also studied. Poisson regression analysis was used to compute adjusted incidence and mortality rate ratios (IRRs, MRRs).

Findings

Using health and administrative registers, we performed a population-based cohort study of 4,412,382 individuals (mean age 48 years; 51% females). In all, 257,450 (5·8%) individuals had a PCR-confirmed SARS-CoV-2 infection. After adjustment for age, calendar time, and sex, we found that especially people experiencing homelessness had high risk of hospitalisation (IRR 4·36, 95% CI, 3·09-6·14), intensive care (IRR 3·12, 95% CI 1·29-7·52), and death (MRR 8·17, 95% CI, 3·66-18·25) compared with people without such experiences, but increased risk was found for all studied groups. Furthermore, after full adjustment, including for status of vaccination against SARS-CoV-2 infection, individuals with experiences of homelessness and a PCR-confirmed SARS-CoV-2 infection had 41-times (95% CI, 24·84-68·44) higher risk of all-cause death during the study period compared with individuals without. Supported psychiatric housing was linked to almost 3-times higher risk of hospitalisation and 60-day mortality following SARS-CoV-2 infection compared with the general population with other living circumstances.

Interpretation

Socially marginalised and psychiatrically vulnerable individuals had substantially elevated risks of adverse health outcomes following SARS-CoV-2 infection. The results highlight that pandemic preparedness should address inequalities in health, including infection prevention and vaccination of vulnerable groups.

Funding

Novo Nordisk Foundation.

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.