by Fernanda Martins Iunes, Thaís Aranha Rossi, Fabiane Soares, Thiago S Torres, Valdilea G. Veloso, Débora Castanheira, Nathalia Suzart, Felipe Fagundes Soares, Alexandro Gesner Gomes dos Santos, Diana Zeballos, Ines Dourado, Laio Magno This study aimed to examine the factors associated with Coronavirus disease 2019 (COVID-19) vaccination schedule completion among adults in socially vulnerable neighborhoods in two Brazilian state capitals.
This cross-sectional study analyzed the data of individuals who attended primary healthcare (PHC) units in Salvador and Rio de Janeiro between July 2022 and May 2023. Data were collected using a structured sociobehavioral questionnaire.
The outcome variable was COVID-19 vaccination schedule completion, defined as receiving ≥1 booster dose in the primary series (i.e., first and/or second dose or single-dose vaccine) plus one booster dose. The association between predictor variables and vaccination schedule completion was evaluated using multiple logistic regression.
A total of 7,193 participants who reported having received ≥1 dose was included, 79.35% had completed the vaccination schedule.
This cross-sectional analysis investigates factors linked to completing the COVID-19 vaccination schedule among adults residing in socially vulnerable neighborhoods in two Brazilian state capitals.
The investigation drew on data from individuals who sought care at primary health care units in Salvador and Rio de Janeiro between July 2022 and May 2023.
Data collection relied on a structured sociobehavioral questionnaire.
The research employed multiple logistic regression to assess associations between predictor variables and vaccination schedule completion.
Outcome definition: vaccination schedule completion was set as receipt of at least one booster after the primary series (whether through two-dose or single-dose vaccines) plus an additional booster dose.
The analysis included 7,193 participants who reported having received at least one vaccine dose.
The study points to sociodemographic and health-system engagement factors as meaningful determinants of vaccination adherence within socially vulnerable urban populations.
It highlights that older age, female gender, higher education, multimorbidity, integrated or ongoing contact with healthcare services, and recent primary care utilization correlate with higher completion rates.
In contrast, faith-based affiliation (Evangelical) and crowded living conditions appear linked to lower completion.
The report notes limitations inherent to cross-sectional designs, including the inability to establish causal direction.
The scope is limited to adults in two Brazilian capitals and to individuals who reported at least one vaccine dose; these aspects may affect generalizability beyond similar settings or populations.