TITLE

Effects of vaccination and population structure on influenza epidemic spread in the presence of two circulating strains

AUTHOR(S)
Alexander, Murray E.; Kobes, Randy
PUB. DATE
January 2011
SOURCE
BMC Public Health;2011 Supplement 1, Vol. 11 Issue Suppl 1, p1
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
Background: Human influenza is characterized by seasonal epidemics, caused by rapid viral adaptation to population immunity. Vaccination against influenza must be updated annually, following surveillance of newly appearing viral strains. During an influenza season, several strains may be co-circulating, which will influence their individual evolution; furthermore, selective forces acting on the strains will be mediated by the transmission dynamics in the population. Clearly, viral evolution and public health policy are strongly interconnected. Understanding population-level dynamics of coexisting viral influenza infections, would be of great benefit in designing vaccination strategies. Methods: We use a Markov network to extend a previous homogeneous model of two co-circulating influenza viral strains by including vaccination (either prior to or during an outbreak), age structure, and heterogeneity of the contact network. We explore the effects of changes in vaccination rate, cross-immunity, and delay in appearance of the second strain, on the size and timing of infection peaks, attack rates, and disease-induced mortality rate; and compare the outcomes of the network and corresponding homogeneous models. Results: Pre-vaccination is more effective than vaccination during an outbreak, resulting in lower attack rates for the first strain but higher attack rates for the second strain, until a "threshold" vaccination level of ~30-40% is reached, after which attack rates due to both strains sharply dropped. A small increase in mortality was found for increasing pre-vaccination coverage below about 40%, due to increasing numbers of strain 2 infections. The amount of cross-immunity present determines whether a second wave of infection will occur. Some significant differences were found between the homogeneous and network models, including timing and height of peak infection(s). Conclusions: Contact and age structure significantly influence the propagation of disease in the population. The present model explores only qualitative behaviour, based on parameters derived for homogeneous influenza models, but may be used for realistic populations through statistical estimates of inter-age contact patterns. This could have significant implications for vaccination strategies in realistic models of populations in which more than one strain is circulating.
ACCESSION #
59334865

 

Related Articles

  • Confronting Potential Influenza A (H5N1) Pandemic with Better Vaccines. Haque, Azizul; Hober, Didier; Kasper, Lloyd H. // Emerging Infectious Diseases;Oct2007, Vol. 13 Issue 10, p1512 

    Influenza A (H5N1) viruses are strong candidates for causing the next influenza pandemic if they acquire the ability for efficient human-to-human transmission. A major public health goal is to make efficacious vaccines against these viruses by using novel approaches, including cell-culture...

  • Avian Flu Pandemic.  // Background Information Summaries;1/2/2011, p3 

    This article reports on a strain of influenza A named H5N1, carried by wild birds and thus popularly called avian (or bird) flu, which has raised concerns of a world pandemic that could result in millions of deaths. Public health experts are especially worried that a mutation of the virus could...

  • Optimizing Tactics for Use of the U.S. Antiviral Strategic National Stockpile for Pandemic Influenza. Dimitrov, Nedialko B.; Goll, Sebastian; Hupert, Nathaniel; Pourbohloul, Babak; Meyers, Lauren Ancel // PLoS ONE;2011, Vol. 6 Issue 1, p1 

    In 2009, public health agencies across the globe worked to mitigate the impact of the swine-origin influenza A (pH1N1) virus. These efforts included intensified surveillance, social distancing, hygiene measures, and the targeted use of antiviral medications to prevent infection (prophylaxis). In...

  • US Officials Bullish on Flu Vaccine Supply.  // Clinical Infectious Diseases;7/1/2005, Vol. 41 Issue 1, p1 

    The article reports on the 2005 supply of flu vaccine in the U.S. Centers for Disease Control and Prevention Director Dr. Julie Gerberding said if all companies currently planning to produce vaccine come through, the nation could end up with more than 190 million doses--the most ever for a flu...

  • Special Report: H1N1 Postmortem.  // Hospital Infection Control & Prevention;Apr2010, Vol. 37 Issue 4, p37 

    The article discusses health issues after the H1N1 threat, including preventing other infections, the issue of mandatory flu vaccinations and respiratory protection of health care workers.

  • Kids and Flu Shots.  // Pediatrics for Parents;2004, Vol. 21 Issue 3, p9 

    The article focuses on the Centers for Disease Control and Prevention, which made it official that children six to twenty three months old should receive flu shots this fall. In the past, the flu shot was recommended only for children two years old and older.

  • Pandemik 2009 H1N1 influenza enfeksiyonları. Hacımustafaoğlu, Mustafa // Turkish Pediatrics Archive / Turk Pediatri Arsivi;jun2010 supplement, Vol. 45, p31 

    In early spring 2009 an outbreak of H1N1 influenza A virus infection was detected in Mexico, spreaded quickly, and on June 11 2009, World Health Organization raised its pandemic level to phase 6. This novel H1N1 pandemic influenza A virus represented a quadruple reassortment of swine, human and...

  • Tiered Use of Inactivated Influenza Vaccine in the Event of a Vaccine Shortage.  // JAMA: Journal of the American Medical Association;9/14/2005, Vol. 294 Issue 10, p1204 

    Discusses the tiered use of inactivated influenza vaccine when there is a vaccine shortage in the United States. The estimated number of doses of inactivated vaccine and attenuated vaccine needed for the 2005-2006 influenza season, which is calculated by the Advisory Committee on Immunization...

  • Modeling Optimal Age-Specific Vaccination Strategies Against Pandemic Influenza. Lee, Sunmi; Golinski, Michael; Chowell, Gerardo // Bulletin of Mathematical Biology;Apr2012, Vol. 74 Issue 4, p958 

    In the context of pandemic influenza, the prompt and effective implementation of control measures is of great concern for public health officials around the world. In particular, the role of vaccination should be considered as part of any pandemic preparedness plan. The timely production and...

Share

Read the Article

Courtesy of VIRGINIA BEACH PUBLIC LIBRARY AND SYSTEM

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics