The COVID-19 pandemic exposed deep structural asymmetries in health systems while simultaneously revealing their adaptive capacities under extreme systemic stress. In Brazil, the Unified Health System (Sistema Único de Saúde – SUS) experienced both fragmentation pressures and remarkable resilience responses, largely mediated by its decentralized governance structure and the strategic role of Primary Health Care (PHC). This article provides an in-depth analytical examination of the post-pandemic resilience of the Brazilian health system, focusing on the extent to which PHC operates as an infrastructural, relational, and epistemic foundation for system continuity, adaptation, and transformation. Drawing on an integrative theoretical synthesis of health systems resilience literature, PHC theory, and the Brazilian health reform trajectory, the article conceptualizes resilience not as mere recovery, but as a dynamic capacity involving absorption, adaptation, and transformative restructuring. The analysis demonstrates that PHC in Brazil functioned as a critical buffering layer during the pandemic, sustaining essential services, enabling territorial surveillance, and mitigating inequities through community-based care. However, it also reveals persistent structural constraints, including chronic underfunding, fragmented digital integration, workforce instability, and uneven regional implementation. The article argues that the post-pandemic period represents a critical “window of opportunity” for reconfiguring SUS resilience through PHC strengthening. It concludes that resilience is not an emergent property of hospital capacity alone, but rather a systemic outcome rooted in primary care governance, territorial embeddedness, and intersectoral coordination.
Oldair Donizete Galeni1, Ainoã Efa Fernandes e Souza2, Juliana Aparecida Pereira Ribeiro3, Dulcyane Ferreira de Oliveira4, Teomilla Augusta Martins5, Ana Carla Mota Bastos6, Regina Gabriela Caldas de Moraes7, Cassimar Dias Ferreira8 (Thu,) studied this question.