The Role of COVID-19 Vaccination in Serological and Infectious Response in the Xokós Indigenous Community

Objectives: This study aims to examine the serological and infectious characteristics of the Xokós indigenous community in Brazil, both prior to and following COVID-19 immunization; Methods: Immunofluorescence assays were employed to identify the SARS-CoV-2 viral antigen, while IgM and IgG antibody tests for COVID-19 were utilized to assess the participants’ infectious and serological profiles in July 2020, before the commencement of the COVID-19 vaccination campaign, and in March 2022, during the booster dose vaccination campaign; Results: The majority of participants (n = 22) were female, with an average age of 42.20 years. The most prevalent comorbidity was hypertension (60%; n = 9), followed by hypertension associated with diabetes (20%; n = 3). No statistically significant correlation was found between the timing of vaccination and the levels of antigens or IgM. However, the prevalence of reactive antigens and IgM was 13.3% (n = 4) in the pre-vaccination group and 3.3% (n = 1) in the post-vaccination group. A statistically significant difference in IgG production was observed before and after vaccination (χ2(1) = 39.095, p < 0.01), as well as differences in IgG antibody detection before and after vaccination and in the vaccines used. Participants showed a higher probability of reactive IgG antibodies following vaccination; Conclusions: Our data demonstrate the beneficial effects of vaccination on the indigenous community, highlighting that continued immunization is a crucial step in protecting indigenous health and preventing severe outbreaks and deaths associated with the disease.