Drivers and prevalence of COVID-19 vaccine uptake among homeless and precariously housed people in France: a cross-sectional population-based study (preprint)

Background Few global data exist regarding COVID-19 vaccine coverage in people experiencing homelessness (PEH) or precariously housed (PH) who are at high risk for COVID-19 infection, hospitalization, and death. Given the absence of documented French data, we aimed to determine COVID-19 vaccine coverage in PEH/PH in France, and its drivers. Methods We carried out a cross-sectional study following a two-stage cluster-sampling design in Ile-de-France and Marseille, France, in late 2021. Participants aged over 18 years were recruited where they slept the previous night and then stratified for analysis into three housing groups (Streets, Accommodated, and Housed). Interviews were conducted face-to-face in the participant's preferred language. Multilevel univariate and multivariable logistic regression models were built. Findings 3,690 individuals were surveyed: 855 in the Housed stratum, 2,321 in the Accommodated stratum and 514 in the Streets stratum. 76.2% (95%CI 74.3-78.1) reported receiving at least one COVID-19 vaccine dose. Vaccine uptake varied by stratum, with uptake highest (85.6%; reference) in Housed, followed by Accommodated (75.4%; AOR=0.79; 95%CI 0.51-1.09 vs Housed) and lowest in Streets (42.0%; AOR=0.38; 95%CI 0.25-0.57 vs Housed). Use for vaccine certificate, socioeconomic drivers, and vaccine hesitancy explained vaccine coverage. Interpretation In France, PEH/PH are less likely than the general population likely to receive COVID-19 vaccines; with the most excluded being the least likely. The influence of both structural drivers and vaccine beliefs in PEH/PH reinforce the importance of targeted outreach, on-site vaccination and sensitisation activities to further vaccine uptake. Funding Sante Publique France, Agence Nationale de Recherches sur le Sida/Capnet, Agence Regionale de Sante-Ile de France, Medecins Sans Frontieres, and Societe de Pathologie Infectieuse de Langue Francaise.

Residential Mobility of a Cohort of Homeless People in Times of Crisis: COVID-19 Pandemic in an European Metropolis (preprint)

Most vulnerable individuals are particularly affected by the COVID-19 pandemic. This study takes place in a large city in France. The aim of this study is to describe the mobility of the homeless population at the begin-ning of the health crisis and to analyze its impact in terms of COVID-19 prevalence. From June to August 2020 and September to December 2020, 1272 homeless people were invited to be tested for SARS-CoV-2 antibodies and virus in and completed questionnaires. Our data show that homeless populations are sociologically dif-ferent depending on where they live. We show that people living on the street were most likely to be relocated to emergency shelters than other inhabitants. Some neighborhoods are points of attraction for homeless peo-ple in the city while others emptied during the health crisis, which had consequences for virus circulation. People with a greater number of different dwellings reported became more infected. This first study of the mo-bility and epidemiology of homeless people in time of pandemic provides unique information about mobility mapping, sociological factors of this mobility, mobility at different scales and epidemiological consequences. We suggest that homeless policies need to be radically transformed since actual model exposes people to infection in emergency.

Cumulative Incidence of SARS-CoV-2 Infection Within the Homeless Population: Insights From a Citywide Longitudinal Study (preprint)

Background: Studies showed high prevalence of SARs-CoV-2 among homeless people in shelters, but no longitudinal studies confirmed these findings, put them into perspective, or considered homeless populations beyond shelters. Methods: All homeless adults sleeping rough, in slums or squats, in emergency shelters or transitional accommodation in Marseille were eligible. There were two testing sessions, 3 months apart, during which each participant was tested for anti-SARS-CoV-2 antibodies and completed a face-to-face surveys. The primary outcome was the occurrence of a seroconversion event defined as a biologically confirmed SARS-CoV-2 infection. Cox proportional hazards regression models and Kaplan-Meier survival analysis with log-rank test were performed to evaluate risk factors associated with seroconversion. Local data from a national seroprevalence survey were used for comparison between homeless people and the general population.Findings: A total of 1249 people were included. SARS-CoV-2 seroprevalence increased from 6.0% [4.7-7.3] during the first session to 18.9% [16.0-21.7] during the second one, compared to 3.0% [1.9-4.2] and 6.5% [4.5-8.7] in the general population. Factors significantly associated with an increased risk of COVID-19 infection were: having stayed in emergency shelters (1.93 [1.18 – 3.15]), being an isolated parent (1.64 [1.07-2.52]) and having contact with more than 5-15 people per day (1.84 [1.27 – 2.67]). By contrast, smoking (0.46 (0.32 – 0.65)), having financial resources (0.70 (0.51 – 0.97)) and psychiatric or addictive comorbidities (0.52 (0.32 – 0.85)) were associated with a lower risk.Interpretation: We confirm that homeless people have higher infection rates than the general population, with increased risk in emergency shelters.Funding Information: French Directorate of Health care facilities (DGOS) – research grant PHRC COVID-19 (COVID-homeless 0047)Declaration of Interests: The authors declare that they have no competing interests. Ethics Approval Statement: All participants provided a written informed consent. The COVIDHomeless study was designed and carried out in compliance with the Declaration of Helsinki and with legal and regulatory provisions. It was approved by the ethics committee on May 28, 2020 (CPP IDF VI - number 44-20; ID: 2020-AO1398-31). The database was anonymized and declared to the French data protection commission (Commission Nationale de l’Informatique et des Libertés, CNIL, n°2018172v0).

Seroprevalence of SARS-CoV-2 Antibodies Among Homeless People Living Rough, in Shelters and Squats: A Large Population-Based Study in France (preprint)

Background: Overcrowded housing, as well as inadequate sanitary conditions, contribute to making homeless people particularly vulnerable to the SARS-CoV-2 infection. We aimed to assess the seroprevalence of the SARS-CoV-2 infection among people experiencing homelessness on a large city-wide scale in France, taking into account different community settings. Methods: A consortium of outreach teams in 48 different locations including streets, slums, squats, emergency or transitional shelters and drop-in centres participated in the inclusion process. All participants consented to receive a validated rapid assay for immunoglobulins M (IgM) and G (IgG) antibodies and to answer a questionnaire on medical health conditions, comorbidities, historic of symptoms compatible with COVID-19, with a retrospective calendar of types of accommodation since COVID-19 crisis. Results: From June 01 to August 05, 2020, 1,156 homeless participants were enrolled in the study and tested. Seroprevalence of SARS-CoV-2 IgG/IgM antibodies was 5.6% (95%CI 2.3–7.0), with a range of 2.2% in people living on the streets to 8.1% in people living in emergency shelters (P=0.009). Around one third of the seropositive participants reported symptoms with COVID-19. Compared to the general population in Marseille (3.6%), the homeless population living in the same urban area experienced an significant increased risk of SARS-CoV-2 infection (|z|=3.65 > 1.96). Conclusion: These results highlight the need for organizing regular screening to prevent clusters forming in homeless accommodations and for providing basic resources for health maintenance.