This article is part of the supplement: Mathematical Modelling of Influenza

Open Access Research

Reactive strategies for containing developing outbreaks of pandemic influenza

Sigrún Andradóttir1, Wenchi Chiu1, David Goldsman1*, Mi Lim Lee1, Kwok-Leung Tsui1, Beate Sander234, David N Fisman5 and Azhar Nizam6

Author Affiliations

1 H. Milton Stewart School of Industrial and Systems Engineering, Georgia Institute of Technology, Atlanta, Georgia, 30332, USA

2 Toronto Health Economics and Technology Assessment Collaborative, Toronto, Ontario, M5S 3M2, Canada

3 Department of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, M5T 3M6, Canada

4 Division of Clinical Decision-Making and Health Care Research, University Health Network, Toronto, Ontario, M5G 2C4, Canada

5 Department of Epidemiology, Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, M5T 3M7, Canada

6 Department of Biostatistics and Bioinformatics, Emory University, Atlanta, Georgia, 30322, USA

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BMC Public Health 2011, 11(Suppl 1):S1  doi:10.1186/1471-2458-11-S1-S1

Published: 25 February 2011



In 2009 and the early part of 2010, the northern hemisphere had to cope with the first waves of the new influenza A (H1N1) pandemic. Despite high-profile vaccination campaigns in many countries, delays in administration of vaccination programs were common, and high vaccination coverage levels were not achieved. This experience suggests the need to explore the epidemiological and economic effectiveness of additional, reactive strategies for combating pandemic influenza.


We use a stochastic model of pandemic influenza to investigate realistic strategies that can be used in reaction to developing outbreaks. The model is calibrated to documented illness attack rates and basic reproductive number (R0) estimates, and constructed to represent a typical mid-sized North American city.


Our model predicts an average illness attack rate of 34.1% in the absence of intervention, with total costs associated with morbidity and mortality of US$81 million for such a city. Attack rates and economic costs can be reduced to 5.4% and US$37 million, respectively, when low-coverage reactive vaccination and limited antiviral use are combined with practical, minimally disruptive social distancing strategies, including short-term, as-needed closure of individual schools, even when vaccine supply-chain-related delays occur. Results improve with increasing vaccination coverage and higher vaccine efficacy.


Such combination strategies can be substantially more effective than vaccination alone from epidemiological and economic standpoints, and warrant strong consideration by public health authorities when reacting to future outbreaks of pandemic influenza.