Sistema FMUSP-HC: Faculdade de Medicina da Universidade de São Paulo (FMUSP) e Hospital das Clínicas da FMUSPPINTO, Jose Paulo GuedesMAGALHAES, Patricia CamargoFIGUEIREDO, Gerusa MariaALVES, DomingosANGEL, Diana Maritza Segura2024-02-152024-02-152023CADERNOS DE SAUDE PUBLICA, v.39, n.11, article ID e00109522, 14p, 20230102-311Xhttps://observatorio.fm.usp.br/handle/OPI/57994After four months of fighting the pandemic, the city of Sao Paulo, Brazil, en-tered a phase of relaxed social distancing measures in July 2020. Simulta-neously, there was a decline in the social distancing rate and a reduction in the number of cases, fatalities, and hospital bed occupancy. To understand the pandemic dynamics in the city of Sao Paulo, we developed a multi-agent simulation model. Surprisingly, the counter-intuitive results of the model fol-lowed the city's reality. We argue that this phenomenon could be attributed to local bubbles of protection that emerged in the absence of contagion net-works. These bubbles reduced the transmission rate of the virus, causing short and temporary reductions in the epidemic curve - but manifested as an un-stable equilibrium. Our hypothesis aligns with the virus spread dynamics ob-served thus far, without the need for ad hoc assumptions regarding the natu-ral thresholds of collective immunity or the heterogeneity of the population's transmission rate, which may lead to erroneous predictions. Our model was designed to be user-friendly and does not require any scientific or program-ming expertise to generate outcomes on virus transmission in a given loca-tion. Furthermore, as an input to start our simulation model, we developed the COVID-19 Protection Index as an alternative to the Human Development Index, which measures a given territory vulnerability to the coronavirus and includes characteristics of the health system and socioeconomic development, as well as the infrastructure of the city of Sao Paulo.engopenAccessSocial DistancingCOVID-19Virus SheddingheterogeneitydurationepidemicarticleCopyright CADERNOS SAUDE PUBLICA10.1590/0102-311XEN109522Public, Environmental & Occupational Health1678-4464