|CASTRO, FELIPA - Laboratorio Avi-Mex, Sa De Cv|
|PAZ, GEORGINA - Laboratorio Avi-Mex, Sa De Cv|
|LAZONO, BERNARDO - Laboratorio Avi-Mex, Sa De Cv|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/5/2018
Publication Date: N/A
Technical Abstract: A fowl adenovirus serotype 9, a non-pathogenic large double stranded DNA virus, was developed as a viral vector to express influenza genes as a potential vaccine. Two separate constructs were developed that expressed either the hemagglutinin gene of A/Chicken/Jalisco/2012 (H7) or A/ Chicken/Iowa/2015 (H5) that were modified to have a cleavage site compatible with a low pathogenic avian influenza virus. Specific pathogen free 3 week old white leghorn chickens were vaccinated either subcutaneously with a single dose or orally vaccinated with 2 doses of vaccine and then challenged 3 weeks after the initial vaccination. The H7 vector vaccinated birds were challenged with one of three highly pathogenic avian influenza viruses, representing 3 recent North American isolates. Against the homologous challenge, all the subcutaneously vaccinated birds seroconverted with an average geometric mean hemagglutination inhibition titer of 17.2 and all birds survived challenge with a significant reduction in virus shedding. Against the A/turkey/IN/1403/2016 challenge, all S.C. vaccinated birds survived challenge, had a significant reduction in viral shedding, although only 6 of 8 birds seroconverted to the challenge strain. However, against the A/Chicken/MX/3191/2016 challenge, only one S.C. bird seroconverted to the challenge strain and it was the only bird to survive challenge. The single H5 vaccine group was challenged with the A/turkey/MN/12582/2015 virus and 6 of 8 survived challenge. The birds that were orally vaccinated had poor seroconversion and poor protection from mortality. The fowl adenovirus serotype 9 viral vector was an effective vaccine when matched to the field strain.