Reactive strategies for containing developing outbreaks of pandemic influenza

• Type of Material: Article
• Authors: Sigrun Andradottir, Georgia Institute of Technology; Wenchi Chiu, Georgia Institute of Technology; David Goldsman, Georgia Institute of Technology; Mi Lim Lee, Georgia Institute of Technology; Kwok-Leung Tsui, Georgia Institute of Technology; Beate Sander, University of Toronto; David N. Fisman, University of Toronto; Azhar Nizam, Emory University
• Language: English
• Date: 2011-02-25
• Publisher: BioMed Central
• Publication Version: Final Published Version
• Copyright Statement: © 2011 Andradóttir et al; licensee BioMed Central Ltd.
• License: Creative Commons Attribution 2.0 Generic
• Final Published Version (URL): http://www.biomedcentral.com/1471-2458/11/S1/S1
• Title of Journal or Parent Work: BMC Public Health
• ISSN: 1471-2458
• Volume: 11
• Issue: Suppl 1
• Start Page: 1
• End Page: 15
• Grant/Funding Information: DNF has received grant matching funds from Sanofi Pasteur, which manufactures a vaccine for use against influenza A (H1N1)-2009 outside Canada.
• Research Categories: Biology, Biostatistics; Health Sciences, Epidemiology; Health Sciences, Public Health

Abstract

Background 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. Methods 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. Results 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. Conclusions 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.