Publications by authors named "Alex Jose Leite Torres"

Article Synopsis
  • COVID-19 vaccination among indigenous minors is essential for controlling the pandemic due to their increased vulnerability from limited healthcare.
  • A study was conducted on 98 Brazilian indigenous adolescents, primarily of Guarani ethnicity, to evaluate the immune response to the BNT162b2 vaccine after vaccination.
  • Results showed a significant increase in antibody concentrations and various immune cells, indicating the vaccine's effectiveness, while also highlighting the potential need for booster doses in this population.
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Introduction: Although the adaptive immune responses to the CoronaVac vaccine are known, their dynamics in indigenous communities remain unclear. In this study, we assessed the humoral and cellular immune responses to CoronaVac (Sinovac Biotech Life Sciences, 2021 NCT05225285, Beijing, China), in immunized Brazilian indigenous individuals.

Methods: We conducted a prospective cohort study on indigenous Brazilian people between February 2021 and June 2021.

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This study assessed the seroprevalence of SARS-CoV-2 in 496 asymptomatic individuals from Mato Grosso do Sul, located in Dourados, the largest periurban indigenous area in Brazil, from January 25 to February 4, 2021. The volunteers participated before receiving their first dose of the CoronaVac inactivated vaccine. For screening, blood samples were collected and analyzed using SARS-CoV-2 rapid tests and the enzyme-linked immunosorbent assay (ELISA).

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Article Synopsis
  • * A study analyzed 204 SARS-CoV-2 positive samples, identifying six main lineages with Zeta being the most prevalent, and showed multiple introduction events likely influenced by indigenous mobility.
  • * The mortality rate among the indigenous population was estimated at 1.47%, which was slightly lower than the state average, suggesting potential underreporting and challenges in data consistency.
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Unlabelled: Morais et al. conducted a pioneering study with Brazilian indigenous populations to determine reference values for immunologic cells from healthy adult individuals. The main findings included a higher relative median for T lymphocyte subsets in females than males, and T CD3+, T CD4+, and T CD8+ relative values were statistically different when compared with Brazilian populations from other Brazilian regions.

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Objective: To characterize the immunophenotypic profile of acute leukemias in the population of the state of Bahia, Brazil.

Methods: This is a descriptive, retrospective study. From 2014 to 2018, 796 new cases of acute leukemia were evaluated.

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This cross-sectional observational study that describes the epidemiological data of the first year of the COVID-19 pandemic in the Mato Grosso do Sul State, aimed to demonstrate the differences between indigenous and non-indigenous populations, characterize confirmed cases of COVID-19 according to risk factors related to ethnicity, comorbidities and their evolution and to verify the challenges in facing the disease in Brazil. SIVEP-Gripe and E-SUS-VE, a nationwide surveillance database in Brazil, from March 2020 to March 2021 in Mato Grosso do Sul state, were used to compare survivors and non-survivors from indigenous and non-indigenous populations and the epidemiological incidence curves of these populations. A total of 176,478, including 5,299 indigenous people, were confirmed.

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In this study, we investigated the capacity of the recombinant proteins SpaC, NanH, SodC, and PLD of to trigger protective humoral and cellular immune responses against experimentally induced infection in sheep. The antigens were produced in a heterologous system and were purified by affinity chromatography. Nine sheep were randomly divided into three groups, which were immunized as follows: Group 1 (control)-a mix of adjuvants composed of the inactivated T1 strain of and commercial Montanide™ISA 61 VG (T1M); Group 2-rSpaC, rSodC, rPLD, and T1M; Group 3-rNanH, rSodC, rPLD, and T1M.

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Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the virus responsible for coronavirus 2019 (COVID-19), which was declared a pandemic in March 2020 by the World Health Organization due the rapid spread representing a global health crisis. The disease is characterized by a wide clinical spectrum ranging from asymptomatic forms until severe viral pneumonia, which can to evolve to severe acute respiratory syndrome, especially in elderly patients and/or with comorbidities. An efficient assembly of the immunological response of the patients becomes fundamental against SARS-CoV-2 infection and it has been demonstrating a significant relationship between the severity of the disease and expression profile of the immune cells and the levels of pro-inflammatory cytokines.

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Use of CCR5 antagonists requires previous viral tropism determination. The available methods have high cost, are time-consuming, or require highly trained personnel, and sophisticated equipment. We compared a flow cytometry-based tropism assay with geno2pheno method to determine HIV-1 tropism in AIDS patients, in Bahia, Brazil.

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In Brazil, the existing reference values for T-lymphocytes subsets are based on data originated in other countries. There is no local information on normal variation for these parameters in Brazilian adults and children. We evaluated the normal variation found in blood donors from five large Brazilian cities, in different regions, and in children living in Salvador, and Rio de Janeiro.

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Acute HIV infection is rarely recognized as the signs and symptoms are normally unspecific and can persist for days or weeks. The normal HIV course is characterized by a progressive loss of CD4+ cells, which normally leads to severe immunodeficiency after a variable time interval. The mean time from initial infection to development of clinical AIDS is approximately 8-10 years, but it is variable among individuals and depends on a complex interaction between virus and host.

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This study evaluated total lymphocyte count (TLC) as a substitute marker for CD4+ cell counts to identify patients who need prophylaxis against opportunistic infection (CD4 < 200 cells/mm(3)) and patients with CD4 < 350 cells/mm(3) (Brazilian threshold value of CD4 count to define AIDS). We evaluated TLC and CD4+ cells count of 1,174 HIV-infected patients, in Salvador, Brazil, from May 2003 to September 2004. CD4+ cell counts were performed by flow cytometry, and TLC was measured with an automated hematological counter.

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