Social determinants of adult COVID-19 vaccine acceptance and uptake in a Brazilian urban informal community: a longitudinal time-to-event study

Publication date: Nov 27, 2023

Residents of informal urban settlements have a high risk of COVID-19 exposure and have less access to medical care, making vaccine-driven prevention critical in this vulnerable population. Despite robust vaccination campaigns in Brazil, vaccine uptake and timing continue to be influenced by social factors and contribute to health disparities. To address this, we conducted a sequential survey in a cohort of 711 adults in an urban favela in Salvador, Brazil where participants were interviewed in 2020, before vaccines were rolled out, and in 2022, after primary and booster dose distribution. We collected data on demographics, social characteristics, and COVID-19 vaccination status and intent. Primary series uptake was high (91.10% for 1st dose and 94.74% for 2nd dose among eligible); however, booster uptake was lower (63.51% of eligible population) at the time of the second interview, suggesting a decreasing interest in vaccination. To account for both vaccine refusal and delays, we conducted a Cox time-to-event analysis of dose uptake using sequential independent outcomes. Exposure times were determined by dose eligibility date to account for age and comorbidities. Intent to vaccinate in 2020 (hazard ratio [HR]: 1.54, CI: [1.05, 1.98]) and age (HR: 1.27, CI: [1.01, 2.08]) were associated with higher vaccination rates for the 1st dose. Males were less likely to receive the 1st dose (HR: 0.61, CI: [0.35, 0.83]), and 2nd dose uptake was lower for those identifying with Pentecostalism (HR: 0.49, CI: [0.37, 0.66]) and without a religion (HR: 0.49, CI: [0.37, 0.66]) compared to Catholics, with the latter association disappearing after controlling by age. Risk perception was associated with 2nd dose uptake (HR: 1.15, CI: [1.08, 1.26]). The role of sex and religion in vaccination behavior highlights the need for targeted outreach and interfacing with local organizations. The data offers lessons to build a long-term COVID-19 vaccination strategy beyond availability.

Concepts Keywords
Brazil Allowed
Pentecostalism Certified
Poorest Covid
Vaccination2728 Doi


Type Source Name
disease VO COVID-19 vaccine
disease VO time
disease MESH COVID-19
disease VO vaccine
disease VO population
disease VO vaccination
disease VO dose
disease IDO country
disease MESH influenza
drug DRUGBANK Ribostamycin
disease VO Gap
disease IDO history
disease MESH chronic illness
disease MESH lost to follow up
disease VO vaccinated
disease IDO process
disease VO vaccination dose
disease MESH uncertainty
disease IDO algorithm
disease VO immunization
disease VO document
disease VO effective
disease VO vaccination coverage
drug DRUGBANK Albendazole
drug DRUGBANK Serine
drug DRUGBANK Coenzyme M
disease MESH Polio
drug DRUGBANK Clarithromycin
disease VO effectiveness
disease VO organ
disease VO monthly

(Visited 1 times, 1 visits today)