Background: COVID-19 increased health inequalities worldwide. Even among healthcare workers, social-economical features enhanced the risk of infection (having positive serology) during the first outbreak. The Omicron variant changed the pandemic course and differs from previous variants in many aspects (molecular, clinical, and epidemiological). Herein, we investigated if the profile of our hospital SARS-CoV-2-positive workers during the Omicron outbreak was the same as the first COVID-19 wave. Methods: Socio-demographics, previous infection, and vaccine status of 351 healthcare workers from our institution during the Omicron outbreak were compared between SARS-CoV-2-negative and -positive workers, using chi-square tests. These data were confronted with the profile observed at the beginning of the pandemic. Results: Compared to the original COVID-19 wave, higher odds of SARS-CoV-2 positivity in highly exposed workers in our hospital and a loss of impact of public transportation and other socio-demographic features in SARS-CoV-2 transmission were observed. Conclusions: Our data suggest the current phase of the pandemic is associated with a reduction of social inequalities among healthcare workers in Rio de Janeiro, possibly due to vaccine-associated protection. Therefore, a worldwide effort to advance vaccination coverage, especially for healthcare workers in developing countries, should be reinforced.

COVID-19 perturbs the renin-angiotensin system (RAAS) and inflammatory pathways, shaping disease severity. Soluble ACE2 (sACE2) and angiotensin II (Ang II) are central regulators of vascular and immune homeostasis. We profiled plasma from COVID-19 patients and controls using ELISA, together with 48 cytokine profiling and clinical data. Both sACE2 and Ang II were significantly elevated in patients. Increased Ang II was associated with oxygen supplementation and dyspnea, and negatively correlated with IL-3, whereas sACE2 correlated with IL-13 and FGF. Comorbidities modulated cytokine expression: diabetes mellitus was linked to reduced LIF and MCP-1, hypertension to decreased LIF and increased IP-10, and obesity to elevated IL-12p70. Age correlated with TNF and HGF, and reduced oxygen saturation was associated with lower LIF. These findings reveal that acute COVID-19 disrupts RAAS and amplifies immune dysregulation, with Ang II emerging as a pivotal mediator of respiratory compromise and inflammatory imbalance, underscoring its potential as a biomarker and therapeutic relevance.