Geographic variation in migration background and SARS-CoV-2 vaccination uptake in the Madrid region, Spain: an ecological analysis

Abstract Background People with a migration background have experienced a high burden of SARS-CoV-2 infection and severe disease progression. Promoting vaccination uptake among these groups is crucial, however, in many areas, uptake has remained unevaluated. This study explored the association between migration background and first-dose SARS-CoV-2 vaccination uptake and delay at the geographic-level in the Madrid region, Spain. Methods We performed an ecological study at the postal code (PC) level using registry data in individuals ≥ 20 years old. We examined the percentage of the population receiving first-dose vaccination (i.e., SARS-CoV-2 vaccination uptake) between December 27, 2020 (campaign start) and the date when vaccination saturated by age group (20–39, 40–59, 60–79, ≥ 80 years, maximum January 25, 2022). We examined the percentage of individuals vaccinated after the 90th -percentile of the total vaccinated population of the corresponding age group (i.e., delayed uptake). Using negative binomial regression, we assessed associations between the percentage foreign-born residents, overall and by region (Latin America, Africa, Europe/North America, Asia/Oceania), and both vaccination outcomes, adjusting for sex, age, education, unemployment, households with ≥ 5 members and income. Analyses were further stratified by age group and sex. Results Across 277 PC, vaccination uptake was 85%. The percentage of foreign-born residents was not associated with uptake, except among ≥ 80-year-olds with the percentage born in Asia and Oceania. However, a higher percentage of foreign-born residents was associated with delayed uptake, specifically among those from Latin America and Asia and Oceania (overall and all age groups), Africa (only in ages 20–39), Europe/North America (overall and ages 60–79). Conclusions Vaccination uptake was mostly consistent across PC with varying proportions of foreign-born residents in the Madrid region. The percentage of individuals with delayed uptake was higher in PC with more foreign-born residents. Continued efforts are needed to overcome barriers and ensure timely vaccination for all communities.