da Costa Giulia Souza, Pellanda Lucia Campos, Silva Leonardo Hercílio Florêncio, Dos Santos Rosimar da Rosa Minho, Tovo-Rodrigues Luciana, Genro Bruna Pasqualini, Fiegenbaum Marilu, Genro Júlia Pasqualini
Graduate Program in Biosciences, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, RS, Brazil.
Graduate Program in Pediatrics, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, RS, Brazil.
Clinics (Sao Paulo). 2025 Aug 21;80:100751. doi: 10.1016/j.clinsp.2025.100751.
With frequent new variants of SARS-CoV-2 and vaccine coverage below 50 % in low-income countries, COVID-19 remains a global health challenge, underscoring the need to update evidence-based health strategies and to understand the pandemic from a historical standpoint. Brazil is an important model for study because of the initial widespread infection and subsequent high population adherence to vaccination.
To compare severity outcomes in a setting of initial low vaccination and after mass vaccination (> 95 %) according to COVID-19 test positivity.
A prospective study with 673 patients tested for COVID-19, followed up until final outcome, in an isolation unit in southern Brazil. We compare the main outcomes and symptoms between the three epidemic waves in Brazil.
The vaccination coverage was 0.4 %, 35.0 %, and 97.6 % during the three waves, while severe cases decreased significantly from the first to the third. Black and brown ethnicity were more frequent among cases during the second wave, and lower income was associated with the second and third. In the multivariate analysis, higher heart rate and black and brown ethnicity were new factors associated with positive diagnosis and severity independently of period.
As vaccination progressed, ethnicity and lower income emerged as increasingly important risk factors, uncovering complex relationships between vaccine coverage and access to information in Brazil. The present results offer a broad view of the clinical features of COVID-19 over almost the entire pandemic period and can help evaluate public policies for subsequent management decisions and strategies to reduce health inequities.
由于新冠病毒频繁出现新变种，且低收入国家的疫苗接种覆盖率低于50%，新冠疫情仍然是一项全球卫生挑战，这凸显了更新循证卫生策略以及从历史角度理解这一流行病的必要性。巴西是一个重要的研究范例，因为该国最初感染广泛，且随后民众对疫苗接种的依从性很高。
根据新冠病毒检测阳性情况，比较初始疫苗接种率较低时和大规模疫苗接种后（>95%）的严重程度结果。
在巴西南部的一个隔离病房对673名接受新冠病毒检测的患者进行了一项前瞻性研究，随访至最终结果。我们比较了巴西三次疫情浪潮中的主要结果和症状。
在这三次疫情浪潮中，疫苗接种覆盖率分别为0.4%、35.0%和97.6%，而重症病例从第一波到第三波显著减少。第二波疫情期间，病例中黑人和棕色人种更为常见，低收入与第二波和第三波疫情相关。在多变量分析中，较高的心率以及黑人和棕色人种是与阳性诊断和严重程度相关的新因素，与疫情时期无关。
随着疫苗接种的推进，种族和低收入成为越来越重要的风险因素，揭示了巴西疫苗接种覆盖率与信息获取之间的复杂关系。本研究结果提供了几乎整个疫情期间新冠病毒临床特征的广泛视图，有助于评估公共政策，以便做出后续管理决策和制定减少健康不平等的策略。
