{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,22]],"date-time":"2026-06-22T21:49:02Z","timestamp":1782164942814,"version":"3.54.5"},"reference-count":0,"publisher":"Medwave Estudios Limitada","issue":"05","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Medwave"],"abstract":"<jats:p>Introduction This article analyzes the prolonged trough phase in the epidemic curve associated with COVID-19 dynamics in Chile during the period July-December 2020, characterized by a relatively stable daily record of 1 000-2500 cases.\n\nMethods Unlike traditional (, )-SIR models, with constant parameters and associated respectively with the transmission and removal rates in the infectious process, which predict unimodal behavior, we propose an approach based on Contagion Mechanics that incorporates a dynamic law for the transmission rate .\n\nResults Using official data from the Department of Health Statistics and Information, we demonstrate how this approach quantitatively captures the observed stabilization, resulting from sustained adherence to non-pharmaceutical measures by the Chilean population. The model reveals that maintaining the infection rate below its intrinsic value required sustained collective effort, enabling controlled management of hospital demand during the pre-vaccination stage.\n\nConclusions Our results validate the usefulness of Contagion Mechanics in explaining complex epidemiological dynamics and offer new perspectives on the population response to prolonged health interventions.<\/jats:p>","DOI":"10.5867\/medwave.2026.05.3191","type":"journal-article","created":{"date-parts":[[2026,6,22]],"date-time":"2026-06-22T21:07:17Z","timestamp":1782162437000},"page":"e3191-e3191","source":"Crossref","is-referenced-by-count":0,"title":["Mechanistic analysis of COVID-19 cases in Chile during the second half of 2020: an SIR model with dynamic transmission rate"],"prefix":"10.5867","volume":"26","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-6515-6880","authenticated-orcid":false,"given":"Fernando","family":"C\u00f3rdova Lepe","sequence":"first","affiliation":[{"name":"Facultad de Ciencias B\u00e1sicas, Universidad Metropolitana de Ciencias de la Educaci\u00f3n, Santiago, Chile"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0002-1769-6393","authenticated-orcid":false,"given":"Ranghely","family":"Hern\u00e1ndez Casta\u00f1eda","sequence":"additional","affiliation":[{"name":"Doctorado en Modelamiento Matem\u00e1tico Aplicado, Universidad Cat\u00f3lica del Maule, Talca, Chile"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1119-9989","authenticated-orcid":false,"given":"Rodrigo","family":"Guti\u00e9rrez","sequence":"additional","affiliation":[{"name":"Facultad de Ciencias B\u00e1sicas, Universidad Cat\u00f3lica del Maule, Talca, Chile"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9723-4978","authenticated-orcid":false,"given":"Juan Pablo","family":"Guti\u00e9rrez Jara","sequence":"additional","affiliation":[{"name":"Centro de Investigaci\u00f3n de Estudios Avanzados del Maule, Universidad Cat\u00f3lica del Maule, Talca, Chile"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"3888","published-online":{"date-parts":[[2026,6,22]]},"container-title":["Medwave"],"original-title":["An\u00e1lisis mecanicista de los casos de COVID-19 en Chile durante el segundo semestre de 2020: un modelo SIR con tasa de transmisi\u00f3n din\u00e1mica"],"deposited":{"date-parts":[[2026,6,22]],"date-time":"2026-06-22T21:07:18Z","timestamp":1782162438000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.medwave.cl\/investigacion\/estudios\/3191.html"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,6,22]]},"references-count":0,"journal-issue":{"issue":"05","published-online":{"date-parts":[[2026,6,22]]}},"URL":"https:\/\/doi.org\/10.5867\/medwave.2026.05.3191","relation":{},"ISSN":["0717-6384"],"issn-type":[{"value":"0717-6384","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,6,22]]}}}