An avian live attenuated master backbone for
potential use in epidemic and pandemic influenza
vaccines
Danielle Hickman,3 Md Jaber Hossain,34 Haichen Song, Yonas Araya,
Alicia Solo ´ rzano and Daniel R. Perez
Department of Veterinary Medicine, University of Maryland, College Park and Virginia-Maryland
Regional College of Veterinary Medicine, 8075 Greenmead Drive, College Park, MD 20742-3711, USA
Open Access Article
vir.sgmjournals.org
Received 12 May 2008
Accepted 10 July 2008
Abstract
The unprecedented emergence in Asia of multiple avian influenza virus (AIV) subtypes with a
broad host range poses a major challenge in the design of vaccination strategies that are both
effective and available in a timely manner. The present study focused on the protective effects of a
genetically modified AIV as a source for the preparation of vaccines for epidemic and pandemic
influenza. It has previously been demonstrated that a live attenuated AIV based on the internal
backbone of influenza A/Guinea fowl/Hong Kong/WF10/99 (H9N2), called WF10att, is effective
at protecting poultry species against low- and high-pathogenicity influenza strains. More
importantly, this live attenuated virus provided effective protection when administered in ovo. In
order to characterize the WF10att backbone further for use in epidemic and pandemic influenza
vaccines, this study evaluated its protective effects in mice. Intranasal inoculation of modified
attenuated viruses in mice provided adequate protective immunity against homologous lethal
challenges with both the wild-type influenza A/WSN/33 (H1N1) and A/Vietnam/1203/04 (H5N1)
viruses. Adequate heterotypic immunity was also observed in mice vaccinated with modified
attenuated viruses carrying H7N2 surface proteins. The results presented in this report suggest
that the internal genes of a genetically modified AIV confer similar protection in a mouse model
and thus could be used as a master donor strain for the generation of live attenuated vaccines for
epidemic and pandemic influenza. |
