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Here, we use mathematical modelling to study the dynamics of COVID-19 in Bahia, a state in northeastern Brazil, considering the influences of asymptomatic\/non-detected cases, hospitalizations, and mortality. The impacts of policies on the transmission rate were also examined. Our results underscore the difficulties in maintaining a fully operational health infrastructure amidst the pandemic. Lowering the transmission rate is paramount to this objective, but current local efforts, leading to a 36% decrease, remain insufficient to prevent systemic collapse at peak demand, which could be accomplished using periodic interventions. Non-detected cases contribute to a\u2009\u223d55% increase in\n                    <jats:italic>R<\/jats:italic>\n                    <jats:sub>0<\/jats:sub>\n                    . Finally, we discuss our results in light of epidemiological data that became available after the initial analyses.\n                  <\/jats:p>","DOI":"10.1038\/s41467-020-19798-3","type":"journal-article","created":{"date-parts":[[2021,1,12]],"date-time":"2021-01-12T13:36:08Z","timestamp":1610458568000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":77,"title":["Mathematical modeling of COVID-19 in 14.8 million individuals in Bahia, Brazil"],"prefix":"10.1038","volume":"12","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7167-8754","authenticated-orcid":false,"given":"Juliane F.","family":"Oliveira","sequence":"first","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4707-3234","authenticated-orcid":false,"given":"Daniel C. P.","family":"Jorge","sequence":"additional","affiliation":[]},{"given":"Rafael V.","family":"Veiga","sequence":"additional","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1594-2311","authenticated-orcid":false,"given":"Moreno S.","family":"Rodrigues","sequence":"additional","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6356-3538","authenticated-orcid":false,"given":"Matheus F.","family":"Torquato","sequence":"additional","affiliation":[]},{"given":"Nivea B.","family":"da Silva","sequence":"additional","affiliation":[]},{"given":"Rosemeire L.","family":"Fiaccone","sequence":"additional","affiliation":[]},{"given":"Luciana L.","family":"Cardim","sequence":"additional","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0090-5443","authenticated-orcid":false,"given":"Felipe A. C.","family":"Pereira","sequence":"additional","affiliation":[]},{"given":"Caio P.","family":"de Castro","sequence":"additional","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4638-4199","authenticated-orcid":false,"given":"Aureliano S. S.","family":"Paiva","sequence":"additional","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7709-5536","authenticated-orcid":false,"given":"Alan A. S.","family":"Amad","sequence":"additional","affiliation":[]},{"given":"Ernesto A. B. F.","family":"Lima","sequence":"additional","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4753-9030","authenticated-orcid":false,"given":"Diego S.","family":"Souza","sequence":"additional","affiliation":[]},{"given":"Suani T. 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