The University of Georgia College of Veterinary Medicine

eorgia Veterinary Scholars Program

GVSP Summer 2007 Scholars

Georgia Veterinary Scholar	Faculty Mentor
	No Photo Available
Rebecca Clarke University of Georgia Class of 2010	Dr. Qingzhong Yu

Generation of a Recombinant Newcastle Disease LaSota Strain Virus Expressing the H5 Gene of Avian Influenza as a Bivalent Vaccine

Rebecca Kay Clarke*, Carlos Estevez, and Qingzhong Yu
Southeast Poultry Research laboratory, USDA, Athens, GA 30605 USA

Abstract

The poultry industry is plagued by several diseases, including Newcastle disease and avian influenza. Both of which have led to great economic losses for the industry. Newcastle disease virus (NDV), due to its zoonotic and highly pathogenic capabilities, has become one of the most serious infectious diseases of poultry. However, it has become better controlled by biosecurity measures and the use of low virulence strains, such as the LaSota strain, for vaccination. Avian influenza (AI) has also become a huge economic loss to the poultry industry, and it is perceived as a potential threat to human health as well. However, due to the nature of the influenza virus, developing an effective and safe vaccine for avian flu is difficult. By using NDV as a vector for AI, an effective and safe multivalent vaccine could be made to protect against both diseases. The goal of this project was to construct a full length cDNA clone by assembling RT- PCR fragments of the LaSota genome into a plasmid vector. Then the selected H5 gene of AI genome was incorporated into the plasmid. A new recombinant virus was rescued from the plasmid in cell culture, and amplified in embryonic chicken eggs. The pathogenicity of the recombinant virus was assessed by using two standard pathotyping tests: the mean death time (MDT) in embryonating eggs and intra cerebral pathogenicity index (ICPI) tests. The genome of the recombinant virus was also sequenced to confirm the fidelity of the virus. By using the LaSota strain of NDV as a backbone for AI, hopefully a low pathogenic and low virulent viral vaccine can be developed to provide effective protection again both AI and NDV.