Laboratory of Pathogen Manipulation, Brazilian Biosciences National Laboratory (LNBio), Department of Virology, CNPEM (Brazilian Center for Research in Energy and Materials), Campinas, Brazil.
Human Population Genomics Laboratory, Biosciences Institute, Department of Genetics and Evolutionary Biology, University of São Paulo, São Paulo, Brazil.
Front Immunol. 2024 Jul 16;15:1359066. doi: 10.3389/fimmu.2024.1359066. eCollection 2024.
The COVID-19 pandemic caused a significant loss of human lives and a worldwide decline in quality of life. Although our understanding of the pandemic has improved significantly since the beginning, the natural history of COVID-19 and its impacts on under-represented populations, such as Indigenous people from America, remain largely unknown. We performed a retrospective serological survey with two Brazilian Indigenous populations (n=624), Tupiniquim and Guarani-Mbyá. Samples were collected between September 2020 and July 2021: a period comprising the dissemination of SARS-CoV-2 variants and the beginning of COVID-19 vaccination in Brazil. Seroconversions against S and N antigens were assessed using three different commercially available ELISA kits. Samples were also used to assess the prevalence of tuberculosis (TB) in the same population (n=529). Seroconversion against SARS-CoV-2 antigens was considered positive if at least one of the three ELISA kits detected levels of specific antibodies above the threshold specified by the manufacturer. In this sense, we report 56.0% (n=349/623) of seroconverted individuals. Relative seroconversion peaked after introduction of the Coronavac vaccine in February 2021. Vaccination increased the production of anti-S IgG from 3.9% to 48.6%. Our results also indicated that 11.0% (n=46/417) of all individuals were positive for TB. Seroconversion to SARS-CoV-2 was similar between individuals with positive tuberculosis test results to those with negative test results. Most vaccinated individuals seroconverted to SARS-CoV-2, indicating that Coronavac may be as protective in individuals from these indigenous groups as observed in the general Brazilian population. COVID-19 severity was minimal regardless of incomplete vaccine coverage, suggesting that vaccination may not be the only factor protecting individuals from severe COVID-19. Tuberculosis is highly prevalent and not associated with increased seroconversion to SARS-CoV-2.
新型冠状病毒肺炎大流行造成了巨大的人类生命损失和全球生活质量下降。尽管自疫情开始以来，我们对疫情的了解有了显著提高，但新型冠状病毒肺炎的自然史及其对代表性不足的人群的影响，如来自美洲的土著人民，在很大程度上仍不清楚。我们对两个巴西土著人群（n=624），图皮南巴人和瓜拉尼-米比亚人进行了回顾性血清学调查。样本采集于 2020 年 9 月至 2021 年 7 月之间：这段时间包括 SARS-CoV-2 变异株的传播和巴西开始接种 COVID-19 疫苗。使用三种不同的商业 ELISA 试剂盒评估针对 S 和 N 抗原的血清转化。还使用样本评估了同一人群中结核病（TB）的流行率（n=529）。如果至少有一种 ELISA 试剂盒检测到特定抗体水平超过制造商规定的阈值，则认为针对 SARS-CoV-2 抗原的血清转化为阳性。在这种情况下，我们报告有 56.0%（n=349/623）的血清转化个体。相对血清转化在 2021 年 2 月科兴疫苗推出后达到峰值。接种疫苗使抗-S IgG 的产生从 3.9%增加到 48.6%。我们的结果还表明，所有个体中有 11.0%（n=46/417）结核病检测结果为阳性。TB 检测结果阳性的个体与阴性的个体之间，针对 SARS-CoV-2 的血清转化率相似。大多数接种疫苗的个体对 SARS-CoV-2 血清转化，这表明科兴疫苗在这些土著人群中的保护作用与在巴西一般人群中的观察结果相似。无论疫苗接种不完全，COVID-19 的严重程度都很低，这表明疫苗接种可能不是保护个体免受严重 COVID-19 的唯一因素。结核病的流行率很高，与 SARS-CoV-2 血清转化率增加无关。
