Backward bifurcation Article 1 Atherosclerosis 1 COVID-19 1 COVID-19 pandemic 1 China 1 Compartmental models 1 Disease/information transmission 1 Forward bifurcation 1 Humans 1 Hysteresis 1 Information Dissemination 1 Optimal control 1 Pandemics 1 SARS-CoV-2 1 The slow-fast system 1 aortic bifurcation 1 coronavirus disease 2019 1 demography 1 disease incidence 1 disease prevalence 1 disease severity 1 disease transmission 1 epidemic 1 health care system 1 human 1 infectious disease 1 information dissemination 1 information system 1 mathematical analysis 1