Vaccination Coverage Against Coronavirus Disease 2019 (COVID-19) in Brazil's Indigenous Population.

Indigenous populations in Brazil were prioritized for coronavirus disease 2019 (COVID-19) vaccination due to their increased vulnerability. The aim of the study was to describe COVID-19 vaccination coverage among Indigenous population across Brazilian regions and Special Indigenous Health Districts (DSEIs; acronym for Distritos Sanitários Especiais Indígenas). A retrospective study was conducted using data from January 17, 2021, to June 27, 2024, obtained from the open-access COVID-19 vaccination database made available by the Brazilian Ministry of Health, covering the 4-year period of the pandemic. The dataset included information on the Indigenous population (number of inhabitants), as well as the number and type of vaccine doses administered (first dose, second dose, single dose, and booster dose). Second dose refers to vaccines requiring a two-dose primary schedule, whereas single-dose refers to vaccines administered as a single primary dose; booster dose refers to any additional dose given after completion of the primary vaccination schedule and, according to the database, was restricted to individuals aged ≥ 18 years. Vaccination coverage was calculated by dividing the number of doses administered by the total Indigenous population, based on estimated from the 2022 Brazilian Institute of Geography and Statistics (IBGE; acronym for Instituto Brasileiro de Geografia e Estatística) Census, and multiplying by 100. The data was analyzed and presented according to Brazil's federative units (states and the Federal District) and DSEIs. A total of 1 490 036 COVID-19 vaccine doses were administered to the Indigenous population. Of these, 631 990 (42%) corresponded to first doses, 551 602 (27%) to second or single doses, and 306 444 (21%) to booster doses. These doses corresponded to vaccination coverage of 89%, 78%, and 43% of the Indigenous population (N = 707 739), respectively. Across the 27 federative units, the lowest coverage for the first dose was observed in Tocantins (83%), Roraima (74%), and Pará (73%), while for second or single doses the lowest rates were found in Amapá (63%), Roraima (60%), and Pará (58%). Among the 34 DSEIs, 13 (38.2%) did not reach 90% coverage for the first dose, and 21 (61.8%) did not reach this threshold for the second or single doses. The lowest coverage levels were identified in Araguaia (65% and 44%), Rio Tapajós (59% and 40%), and Kaiapó do Pará (56% and 34%) for first and second or single doses, respectively. Vaccination coverage against COVID-19 among Brazil's Indigenous population has not fully reached the 90% target recommended by the Brazilian government in alignment with the World Health Organization after 4 years of the pandemic. This gap may be explained by multiple factors, including cultural barriers, remote geographic conditions, and logistical challenges related to vaccine distribution.