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

Abstract

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.

Fig. 1. Study flow chart.

Orange, Blue, Pink and Light Green items represent the original strata prior to statistical analysis. Yellow, Purple and Dark Green items represent groups created for the analysis, based on the most frequent places of living over the past 3 months.

Fig. 2. Standardized vaccination rates: strata vs French general population.

Yellow line is the standardized vaccine uptake for the Precariously Housed stratum (with corresponding 95% CIs yellow band), the purple line is the standardized vaccine uptake for Accommodated stratum and the green line is the standardized vaccine uptake for the Streets stratum. Dark blue line is the standardized vaccine uptake for all strata combined and the grey area is the standardized vaccine uptake for all French adults above 18. Sample sizes are as follows: n = 3690 for the Total sample representing a total standardized population of 100,567, n = 855 for Precariously Housed representing a standardized population of 22,788, n = 1321 for Accommodated representing a standardized population of 73,159 and n = 514 for Streets representing a standardized population of 4620. Population size for French adults above 18 was 52,751,109 as of December 28, 2021. Source data for this figure are available in Supplementary Data 10. A reproducibility guide for figures and tables is available in Supplementary Methods 3.

Fig. 3. Standardized vaccination rates by age categories: strata vs French general population.

Yellow line is the standardized vaccine uptake for the Precariously Housed stratum (with corresponding 95% CIs yellow band), the purple line is standardized vaccine uptake for Accommodated stratum and the green line is the standardized vaccine uptake for the Streets stratum. Dark blue line is the standardized vaccine uptake for all strata combined and the grey area is the standardized vaccine uptake for all French adults above 18. Sample sizes are as follows: n = 3690 for the Total sample representing a total standardized population of 100,567, n = 855 for Precariously Housed representing a standardized population of 22,788, n = 1321 for Accommodated representing a standardized population of 73,159 and n = 514 for Streets representing a standardized population of 4620. Population size for French adults above 18 was 52,751,109 as of December 28, 2021. Source data for this figure are available in Supplementary Data 11. A reproducibility guide for figures and tables is available in Supplementary Methods 3.

Fig. 4. Forest plot (final multilevel mixed logistic regression).

Full dots represent estimates of Adjusted Odds-Ratio and fully capped lines their corresponding 95% Confidence Intervals. Asterisks indicate significant associations and their strength (* for p-values < 0.05, ** for p-values < 0.01 and *** for p-values < 0.001). Sample size for the final model was 3508. Source data are available in Supplementary Data 6. A reproducibility guide for figures and tables is available in Supplementary Methods 3.