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 (ß = 0.05, p < 0.05), healthcare cover (ß = 0.05, p < 0.05), and somebody to accompany the participant for medical appointments (ß = -0.04, p < 0.05); ii) motivation, which included attitudes towards vaccination (ß = 0.55, p < 0.05), press- and poster-based information (ß = 0.03, p < 0.05), and vaccination history (ß = 0.03, p < 0.05); iii) type of housing (ß = 0.13, p < 0.05) and housing stability (ß = 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.

Post-traumatic stress disorder among civilians 6 and 18 months after the January 2015 terrorist attacks in the Paris region.

In the literature, the association between medium and long-term PTSD (post-traumatic stress disorder) after terrorist attack has rarely been described. The objective of our study was to identify the factors associated with PTSD in the medium and longer term among people exposed to a terrorist attack in France. We used data from a longitudinal survey of 123 terror-exposed people interviewed 6-10 (medium term) and 18-22 (long term) months after. Mental health was assessed by the Mini Neuropsychiatric Interview. PTSD in the medium term was associated with history of traumatic events, low levels of social support and severe peri-traumatic reactions, which were in turn associated with high levels of terror exposure. PTSD in the medium term was linked in turn to the presence of anxiety and depressive disorders, which was also linked to PTSD in the longer term. The factors leading to PTSD are different in the medium and long term. In order to improve future support for people exposed to distressing events, it is important to follow up people with intense peri-traumatic reactions, high levels of anxiety and depression and to measure reactions.

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.

Vulnerable populations, such as people experiencing homelessness, are less likely to have a COVID-19 vaccine. We aimed to identify potential reasons for this, by interviewing homeless/precariously housed people in France. We found that although most homeless people have been vaccinated, vaccination rates are lower than the general population. Among the homeless, the least likely to be vaccinated are those living on the streets. The need for vaccine certificates and the support of social workers are positive drivers of vaccine uptake, while influence from family/friends, vaccine hesitancy and fear of the vaccine negatively affect uptake. Providing vaccines on-site and tailoring programs to better target these vulnerable groups should be priorities. Raising awareness by involving trusted third parties is also key to countering negative vaccine beliefs. Our insights apply beyond the COVID-19 crisis, when routinely supporting the health of vulnerable populations.

Seroprevalence and risk factors of exposure to COVID-19 in homeless people in Paris, France: a cross-sectional study.

BACKGROUND: During the COVID-19 lockdown period from March 17 to May 11, 2020, French authorities in Paris and its suburbs relocated people experiencing recurrent homelessness to emergency shelters, hotels, and large venues. A serological survey was done at some of these locations to assess the COVID-19 exposure prevalence in this group. METHODS: We did a cross-sectional seroprevalence study at food distribution sites, emergency shelters, and workers' residences that were provided medical services by Médecins Sans Frontières in Paris and Seine-Saint-Denis in the Ile-de-France region. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody seropositivity was detected by Luciferase-Linked Immunosorbent Assay and Pseudo Neutralization Test. Sociodemographic and exposure related information was collected via a verbal questionnaire to analyse risk factors and associations with various COVID-19 symptoms. FINDINGS: Between June 23 and July 2, 2020, 426 (52%) of 818 individuals recruited tested positive in 14 sites. Seroprevalence varied significantly by type of recruitment site (χ2 p<0·0001), being highest among those living in workers' residences (88·7%, 95% CI 81·8-93·2), followed by emergency shelters (50·5%, 46·3-54·7), and food distribution sites (27·8%, 20·8-35·7). More than two thirds of COVID-19 seropositive individuals (68%, 95% CI 64·2-72·2; 291 of 426) did not report any symptoms during the recall period. COVID-19 seropositivity was strongly associated with overcrowding (medium density: adjusted odds ratio [aOR] 2·7, 95% CI 1·5-5·1, p=0·0020; high density: aOR 3·4, 1·7-6·9, p<0·0001). INTERPRETATION: These results show high exposure to SARS-CoV-2 with important variations between those at different study sites. Living in crowded conditions was the strongest factor associated with exposure level. This study underscores the importance of providing safe, uncrowded accommodation, alongside adequate testing and public health information. FUNDING: Médecins Sans Frontières, Epicentre, Institut Pasteur's URGENCE nouveau coronavirus fund, Total Foundation.