Significance In contrast to predictions of conventional epidemic models, COVID-19 outbreak time series have highly asymmetric shapes, with cases and fatalities declining much more slowly than they rose. Here, we investigate how awareness-driven behavior modulates epidemic shape. We find that short-term awareness of fatalities leads to emergent plateaus, persistent shoulder-like dynamics, and lag-driven oscillations in an SEIR-like model. However, a joint analysis of fatalities and mobility data suggests that populations relaxed mobility restrictions prior to fatality peaks, in contrast to model predictions. We show that incorporating fatigue and long-term behavior change can explain this phenomenon, shed light on when post-peak dynamics are likely to lead to a resurgence of cases or to sustained declines, and inform public health campaigns to control COVID-19. The COVID-19 pandemic has caused more than 1,000,000 reported deaths globally, of which more than 200,000 have been reported in the United States as of October 1, 2020. Public health interventions have had significant impacts in reducing transmission and in averting even more deaths. Nonetheless, in many jurisdictions, the decline of cases and fatalities after apparent epidemic peaks has not been rapid. Instead, the asymmetric decline in cases appears, in most cases, to be consistent with plateau- or shoulder-like phenomena—a qualitative observation reinforced by a symmetry analysis of US state-level fatality data. Here we explore a model of fatality-driven awareness in which individual protective measures increase with death rates. In this model, fast increases to the peak are often followed by plateaus, shoulders, and lag-driven oscillations. The asymmetric shape of model-predicted incidence and fatality curves is consistent with observations from many jurisdictions. Yet, in contrast to model predictions, we find that population-level mobility metrics usually increased from low levels before fatalities reached an initial peak. We show that incorporating fatigue and long-term behavior change can reconcile the apparent premature relaxation of mobility reductions and help understand when post-peak dynamics are likely to lead to a resurgence of cases.
【저자키워드】 public health, Epidemiology, Epidemics, Control, Nonlinear dynamics, 【초록키워드】 COVID-19, fatigue, COVID-19 pandemic, Intervention, Transmission, Population, Epidemic, Health, COVID-19 outbreak, Impact, death, Premature, incidence, Protective, fatality, Analysis, deaths, death rates, observation, reduction, Metrics, help, measure, epidemic peak, declines, asymmetric, Public, joint, initial, caused, reported, the United State, increase, reducing, modulate, reached, explain, sustained, appears, declining, Significance, 【제목키워드】 change,