Presentation Topic :Presentation Topic :

Modeling Human Vaccinating Behaviors Modeling Human Vaccinating Behaviors On a Disease Diffusion NetworkOn a Disease Diffusion Network

PhD Student : Shang XIASupervisor : Prof. Jiming LIU

Department of Computer Department of Computer ScienceScience

August 31, August 31, 2009 2009

10th Postgraduate Research Symposium

ContenContent:t:

1

2

Research Motivation & Objectives

Disease Diffusion Dynamics

3 Individual Behaviors and Interactions

4 AOC Modeling for Local-Global Relationship

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5 Conclusions

In recent years, the emergence of vital epidemic which spreads all over the world have greatly endangered the public health and cause great social impacts.

• Swine Flu Spreading Map

Research Background

SARS, • 2002.11 ~ 2003.07• 8,096 known infected cases and 774 deaths worldwide

Bird Flu, (H5N1) • Recent Years• 65 outbreaks in 2006; 55 in 2007; 11 in 2008.

Swine Flu, (H1N1) • 2009.04 ~ Now• 177,699 infected cases and 1,126 deaths (Aug. 6th)

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Swine Flu World Wide SpreadingSwine Flu World Wide Spreading

04/24/2009 05/04/2009 05/26/2009

06/16/2009 07/06/2009 07/30/2009

Data Source:[1] WHO, ECDC, CPC, HPA (UK), governments [2] BBC Website: http://news.bbc.co.uk/2/hi/uk_news/8083179.stm

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Research Motivation

Disease Diffusion on Human Social Contact Network.

Human is the host of many severe infectious disease. Human’s traveling and interaction spread infection worldwide.

Disease Diffusion changes human’s behavioral pattern. Decision making for vaccination or not.

Individual changes its social interactions.

Human’s contact pattern and demography features characterize disease diffusion dynamics.

Human social contact is the medium of disease diffusion. Human demographical characteristics influence disease infection.

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Research Objectives

Local Individual Reaction PatternLocal Individual Reaction Pattern

Relationship ?Relationship ?

Global Disease Diffusion DynamicsGlobal Disease Diffusion Dynamics

Human Interaction Network Human Interaction Network Disease Infection Model Disease Infection Model

Human Behavioral Mechanism Human Behavioral Mechanism Disease Diffusion Dynamics Disease Diffusion Dynamics

Local-Global Relationship Problem Local-Global Relationship Problem

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Complex Social Disease Diffusion

System

Disease Infection ModelSIV Percolation Model

Individual States in Network Susceptible Individual Infected Individual Vaccinated Individual

Epidemic Transmission in Network

Individual States Transition

Neighbor Infections. Infected individuals die or recover. Vaccination escape potential infection.

Random Selection for a neighbor susceptible. Selection Probability in terms of contact patterns.

( )ij

Trans i jik

k All

wP

w

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1ijw

4ijw

9ijw

3ijw

2ijw

7ijw

8ijw

6ijw

5ijw

Short Range Routine MobileShort Range Routine Mobile

Long Range Chance TravelingLong Range Chance Traveling

Trajectory from home to workplace; Regular shopping in nearby supermarket; Visiting familiar friends or customers.

Enjoying vacations abroad; Business trip to other regions;

Social Contact Network

Human Mobility Dynamics

Human Social Contact Network (1)

Scale Free Network

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Human Social Contact Network (2)

Heterogeneity in demography difference

Heterogeneity in community structure

Disease - Independent host parameters Ages, Gender, Occupation and so on.

Community structure by contact pattern. Community structure by demography characteristics

Disease - Dependent host parameters

Current health status, Susceptibility, Disease transmission rate, etc.

Heterogeneity in contact pattern

Degree Distribution: Neighbor Contacts Edge Weight: Contact Frequency

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Individual Behavioral Mechanism (1)

Individual Vaccination Dilemma

Herd Immunity Dilemma:The individual incentive to vaccinate disappears at high

coverage levels. So the individual incline to persuade other instead of itself to adopt the vaccination.

Self-Interest Decision

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Risk of Vaccination Risk of Infection

Self-Trust Experience Group Psychology Irrational Predictions

Individual Behavioral Mechanism (2)

Individual Decision Making Dynamics Individual Decision Making Dynamics

Perceived Payoff for Vaccination or notPerceived Payoff for Vaccination or not

Records of History Decision MakingRecords of History Decision Making

Environment EstimationEnvironment Estimation

Individuals’ Biased PreferenceIndividuals’ Biased Preference

Environment Evaluation ?V NP P

VaccinationChoice

Non-vaccinationChoice

History Experience

Individual Biased Preference Rules

Y N

W3W2W1

Decision Making Mechanism

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Local - Global Relationship Modeling

Autonomy Oriented Computing

“ AOC emphasize the modeling of autonomy in the entities of a complex system and the self-organization of them in achieving a specific goal ”

-- By Liu (2005)AOC Modeling Framework

Natural System Identification Artificial System Construction Performance Measurement

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AOC Modeling

Natural System Identification

Artificial System Construction

Performance Measurement

Disease Infection Model Individual Contact Network

Individual Interaction Patterns Individual Behaviors Mechanism

Vaccination Patterns Disease Diffusion Dynamics

Multi-Agent System

Autonomous Entities & Self-Organization

Local-Global Relationship

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Result Evaluation Criteria

Social Vaccination Dynamics

Disease Diffusion Dynamics

The proportion of vaccinated individuals.

The Efficacy of Vaccination. •The proportion of vaccinated individuals which are infected by its infectious neighbors.•The proportion of non-vaccinated individuals which are also infected.

The proportion of infected individuals in the whole population.

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The mass outbreak in a certain community.

Individual State Change

Global Epidemic Spreading Dynamics

Disease Diffusion Dynamics Local-Global

Relationship

Local Interaction

Individual Decision Making

History Records

Environment Evaluation

Individual Decision Making

History Records

Environment Evaluation

Social Contact Network

Individual State Transition

Individual Vaccination Choice

Disease Infection

Population Immunization Patterns

Individual Vaccination Decision

Epidemic Spreading Dynamics

Individual State Transition Conclusion

Social Contact Network

Entities Infection Model

Decision Making

Vaccination Dynamics

Disease Diffusion Dynamics

Local Behaviors

Global Dynamics

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Q & AQ & A

Thank You Very Much!