Abstract The rapid rollout of the COVID-19 vaccine raises the question of whether and when the ongoing pandemic could be eliminated with vaccination and non-pharmaceutical interventions (NPIs). Despite advances in the impact of NPIs and the conceptual belief that NPIs and vaccination control COVID-19 infections, we lack evidence to employ control theory in real-world social human dynamics in the context of disease spreading. We bridge the gap by developing a new analytical framework that treats COVID-19 as a feedback control system with the NPIs and vaccination as the controllers and a computational model that maps human social behaviors into input signals. This approach enables us to effectively predict the epidemic spreading in 381 Metropolitan statistical areas (MSAs) in the US by learning our model parameters utilizing the time series NPIs (i.e., the stay-at-home order, face-mask wearing, and testing) data. This model allows us to optimally identify three NPIs to predict infections accurately in 381 MSAs and avoid over-fitting. Our numerical results demonstrate our approach’s excellent predictive power with R 2 > 0.9 for all the MSAs regardless of their sizes, locations, and demographic status. Our methodology allows us to estimate the needed vaccine coverage and NPIs for achieving R e to a manageable level and how the variants of concern diminish the likelihood for disease elimination at each location. Our analytical results provide insights into the debates surrounding the elimination of COVID-19. NPIs, if tailored to the MSAs, can drive the pandemic to an easily containable level and suppress future recurrences of epidemic cycles.
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A multi-agent model to study epidemic spreading and vaccination strategies in an urban-like environment
Abstract Worldwide urbanization calls for a deeper understanding of epidemic spreading within urban environments. Here, we tackle this problem through an agent-based model, in which agents move in a two-dimensional physical space and interact according to proximity criteria. The planar space comprises several locations, which represent bounded regions of the urban space. Based on empirical evidence, we consider locations of different density and place them in a core-periphery structure, with higher density in the central areas and lower density in the peripheral ones. Each agent is assigned to a base location, which represents where their home is. Through analytical tools and numerical techniques, we study the formation mechanism of the network of contacts, which is characterized by the emergence of heterogeneous interaction patterns. We put forward an extensive simulation campaign to analyze the onset and evolution of contagious diseases spreading in the urban environment. Interestingly, we find that, in the presence of a core-periphery structure, the diffusion of the disease is not affected by the time agents spend inside their base location before leaving it, but it is influenced by their motion outside their base location: a strong tendency to return to the base location favors the spreading of the disease. A simplified one-dimensional version of the model is examined to gain analytical insight into the spreading process and support our numerical findings. Finally, we investigate the effectiveness of vaccination campaigns, supporting the intuition that vaccination in central and dense areas should be prioritized.
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- NSF-PAR ID:
- 10217837
- Date Published:
- Journal Name:
- Applied Network Science
- Volume:
- 5
- Issue:
- 1
- ISSN:
- 2364-8228
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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null (Ed.)International Ocean Discovery Program Expedition 385 drilled organic-rich sediments and intruded sills in the off-axis region and axial graben of the northern spreading segment of Guaymas Basin, a young marginal seafloor spreading system in the Gulf of California. Guaymas Basin is characterized by high heat flow and magmatism in the form of sill intrusions into sediments, which extends tens of kilometers off axis, in contrast with the localized volcanism found at most mid-ocean ridge spreading centers. Sill intrusions provide transient heat sources that mobilize buried sedimentary carbon, in part as methane and other hydrocarbons, and drive hydrothermal circulation. The resulting thermal and geochemical gradients shape abundance, composition, and activity of the deep subsurface biosphere of the basin. Drill sites extend over a broad region of Guaymas Basin. Adjacent Sites U1545 and U1546, located ~52 km northwest of the northern Guaymas Basin axial graben, recovered sediment successions to ~540 meters below seafloor (mbsf) (equivalent to the core depth below seafloor, Method A [CSF-A] scale), including a thin sill (a few meters thick) drilled near the bottom of Site U1545 and a massive sill (~355–430 mbsf) at Site U1546 that chemically and physically affects the surrounding sediments. Sites U1547 and U1548, located ~27 km northwest of the axial graben, were drilled to investigate an active sill-driven hydrothermal system evident at the seafloor as an 800 m wide, circular bathymetric high called Ringvent because of its outline of a ring of active vent sites. Ringvent is underlain by a thick sill at shallow depth (Site U1547). Geothermal gradients steepen toward the Ringvent periphery (Holes U1548A–U1548C), and the zones of authigenic carbonate precipitation and of highest microbial cell abundance correspondingly shallow toward the periphery. The underlying sill was drilled several times and yielded diverse igneous rock textures, sediment/sill interfaces, and alteration minerals in veins and vesicles. The Ringvent sill became the target of an integrated, interdisciplinary sampling and research effort that included geological, geochemical, and microbiological components. The thermal, lithologic, geochemical, and microbiological contrasts between the northwestern sites (U1545 and U1546) and the Ringvent sites (U1547 and U1548) form the core scientific observations informing the direct influence of sill-sediment interaction. These observations are supplemented by results from sites that exhibit persistent influence of thermally equilibrated sill intrusions, including supporting long-lived methane cold seeps, as observed at off-axis Sites U1549 and U1552, and the persistent geochemical record of hydrocarbon formation near the sill/sediment contact, as observed at the northern axial trough Site U1550, which confirms observations from Deep Sea Drilling Project (DSDP) Leg 64. Drilling at Site U1551 ~29 km southeast of the axial graben was not successful due to unstable shallow sands, but it confirmed the dominant influence of gravity-flow sedimentation processes southeast of the axial graben. The scientific outcomes of Expedition 385 will (1) revise long-held assumptions about the role of sill emplacement in subsurface carbon mobilization versus carbon retention, (2) comprehensively examine the subsurface biosphere of Guaymas Basin and its responses and adaptations to hydrothermal conditions, (3) redefine hydrothermal controls on authigenic mineral formation in sediments, and (4) yield new insights into the long term influence of sill-sediment interaction on sediments deposited at the earliest stages of seafloor spreading, that is, when spreading centers are proximal to a continental margin. The generally high quality and high degree of completeness of the shipboard data sets present opportunities for inter- and multidisciplinary collaborations during shore-based studies. In comparison to DSDP Leg 64 to Guaymas Basin in 1979, continuous availability of sophisticated drilling strategies (e.g., the advanced piston corer [APC] and half-length APC systems) and numerous analytical innovations greatly improved sample recovery and scientific yield, particularly in the areas of organic geochemistry and microbiology. For example, microbial metagenomics did not exist 40 y ago. However, these technical refinements do not change the fact that Expedition 385 in many respects builds on the foundations of understanding laid by Leg 64 drilling in Guaymas Basin.more » « less
- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1007/s41109-020-00299-7
