The highly pathogenic avian influenza (AI) virus has raised the concern of researchers this past decade. Several outbreaks of H5N1 (a highly pathogenic strain of the AI virus) in 1997, 2003 and 2004, has increased the demands for designing an efficient vaccine against this pathogen. Although H5N1 cannot be transmitted among human beings yet, there is a possibility that the virus could change and easily spread among people, causing a flu pandemic. Recently, H5 infections have been reported in the US backyard and in commercial flocks which have caused considerable economic losses in the poultry industry. In the US, the strategy was condemnation of infected birds without using any vaccinations because once a farm was vaccinated, it would be hard to differentiate between the vaccinated strain and the wild type virus, if an infection were to occur. However, currently, there is an on-going debate about the administration of the bird flu vaccine in the US.
There are different ways that a vaccine can be developed against influenza in general. One of these methods is using a killed virus which gives a good protection rate. Some countries, like China, use this type of vaccine in their poultry industry. However, this method needs the virus to be grown within chicken embryos. Thus, it is time consuming and expensive. Designing a universal vaccine against different strains of the influenza virus is challenging due to the antigenic shift and drift of the virus which cause rapid changes in its structure.
Recently, a nanoparticle-based influenza virus vaccine has attracted the attention of researchers as a useful universal vaccine designing method. In this method, an immunogenic, conserved part of the virus structure is presented repeatedly to the host’s immune system. This allows for a high density immunogenic peptide display. The pathobiology department of the University of Connecticut is working on the construction of an avian flu vaccine based on nanoparticles. Their first paper, published in 2011, showed promising results in both in vitro and in vivo experiments. They are trying to improve the immunogenicity capacity of the vaccine by applying some changes to the nanoparticles’ structure, which will be tested in the BSL3 facility at the University of Delaware soon.
Stay tuned for our upcoming article on genetically modified chickens. This article will focus on another innovative approach, currently under study, that may prevent the spread of bird flu and spare the world the risk of an H5N1 pandemic.
References:
http://www.cdc.gov/flu/avianflu/h5/
http://www.who.int/influenza/human_animal_interface/en/
S. Babapoor, T. Neef, C. Mittelholzer et al. “A novel vaccine using nanoparticle platform to present immunogenic M2e against avian influenza infection,” Influenza Research and Treatment, vol. 2011, Article ID 126794, 12 pages, 2011.
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