109 research outputs found
Impact of network assortativity on epidemic and vaccination behaviour
The resurgence of measles is largely attributed to the decline in vaccine
adoption and the increase in mobility. Although the vaccine for measles is
readily available and highly successful, its current adoption is not adequate
to prevent epidemics. Vaccine adoption is directly affected by individual
vaccination decisions, and has a complex interplay with the spatial spread of
disease shaped by an underlying mobility (travelling) network. In this paper,
we model the travelling connectivity as a scale-free network, and investigate
dependencies between the network's assortativity and the resultant epidemic and
vaccination dynamics. In doing so we extend an SIR-network model with
game-theoretic components, capturing the imitation dynamics under a voluntary
vaccination scheme. Our results show a correlation between the epidemic
dynamics and the network's assortativity, highlighting that networks with high
assortativity tend to suppress epidemics under certain conditions. In highly
assortative networks, the suppression is sustained producing an early
convergence to equilibrium. In highly disassortative networks, however, the
suppression effect diminishes over time due to scattering of non-vaccinating
nodes, and frequent switching between the predominantly vaccinating and
non-vaccinating phases of the dynamics.Comment: 17 pages, 13 figure
A Polarized Temporal Network Model to Study the Spread of Recurrent Epidemic Diseases in a Partially Vaccinated Population
Motivated by massive outbreaks of COVID-19 that occurred even in populations
with high vaccine uptake, we propose a novel multi-population temporal network
model for the spread of recurrent epidemic diseases. We study the effect of
human behavior, testing, and vaccination campaigns on the control of local
outbreaks and infection prevalence. Our modeling framework decouples the
vaccine effectiveness in protecting against transmission and the development of
severe symptoms. Furthermore, the framework accounts for the polarizing effect
of the decision to vaccinate and captures homophily, i.e., the tendency of
people to interact with like-minded individuals. By means of a mean-field
approach, we analytically derive the epidemic threshold. Our theoretical
results suggest that, while vaccination campaigns reduce pressure on hospitals,
they might facilitate resurgent outbreaks, highlighting the key role that
testing campaigns may have in eradicating the disease. Numerical simulations
are then employed to confirm and extend our theoretical findings to more
realistic scenarios. Our numerical and analytical results agree that
vaccination is not sufficient to achieve full eradication, without employing
massive testing campaigns or relying on the population's responsibility.
Furthermore, we show that homophily plays a critical role in the control of
local outbreaks, highlighting the peril of a polarized network structure.Comment: Submitted to IEEE Transactions on Network Science and Engineerin
Coupled Evolutionary Behavioral and Disease Dynamics under Reinfection Risk
We study the interplay between epidemic dynamics and human decision making
for epidemics that involve reinfection risk; in particular, the
susceptible-infected-susceptible (SIS) and the
susceptible-infected-recovered-infected (SIRI) epidemic models. In the proposed
game-theoretic setting, individuals choose whether to adopt protection or not
based on the trade-off between the cost of adopting protection and the risk of
infection; the latter depends on the current prevalence of the epidemic and the
fraction of individuals who adopt protection in the entire population. We
define the coupled epidemic-behavioral dynamics by modeling the evolution of
individual protection adoption behavior according to the replicator dynamics.
For the SIS epidemic, we fully characterize the equilibria and their stability
properties. We further analyze the coupled dynamics under timescale separation
when individual behavior evolves faster than the epidemic, and characterize the
equilibria of the resulting discontinuous hybrid dynamical system for both SIS
and SIRI models. Numerical results illustrate how the coupled dynamics exhibits
oscillatory behavior and convergence to sliding mode solutions under suitable
parameter regimes.Comment: arXiv admin note: text overlap with arXiv:2203.1027
Modeling Coupled Disease-Behavior Dynamics of SARS-CoV-2 Using Influence Networks
SARS-CoV-2, the virus that causes COVID-19, has caused significant human morbidity and mortality since its emergence in late 2019. Not only have over three million people died, but humans have been forced to change their behavior in a variety of ways, including limiting their contacts, social distancing, and wearing masks. Early infectious disease models, like the classical SIR model by Kermack and McKendrick, do not account for differing contact structures and behavior. More recent work has demonstrated that contact structures and behavior can considerably impact disease dynamics. We construct a coupled disease-behavior dynamical model for SARS-CoV-2 by incorporating heterogeneous contact structures and decisions about masking. We use a contact network with household, work, and friend interactions to capture the variation in contact patterns. We allow decisions about masking to occur at a different time scale from disease spread which dramatically changes the masking dynamics. Drawing from the field of game theory, we construct an individual decision-making process that relies on perceived risk of infection, social influence, and individual resistance to masking. Through simulation, we find that social influence prevents masking, while perceived risk largely drives individuals to mask. Underlying contact structure also affects the number of people who mask. This model serves as a starting point for future work which could explore the relative importance of social influence and perceived risk in human decision-making
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