Submitted to: Vaccine
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/22/2006
Publication Date: 4/2/2007
Citation: Toro, H., Tang, D.C., Suarez, D.L., Sylte, M.J., Pfeiffer, J., Van Kampen, K.R. 2007. Protective avian influenza in ovo vaccination with non-replicating human adenovirus vector. Vaccine. 25:2886-2891. Interpretive Summary: Avian influenza virus can infect and cause serious disease in a number of animals including poultry. Although several different vaccines are available for avian influenza, they require the birds to be handled individually for vaccination. This makes vaccination difficult and expensive, particularly during an outbreak. We report that an adenovirus vectored vaccine was prepared that could be used for in ovo vaccination (vaccination of embryo inside the egg). In ovo vaccination is routinely practiced in the poultry industry because it is automated, which reduces cost. The adenovirus vector vaccine with an influenza protein was shown to give measurable antibody titers and protect chickens when challenged with a lethal dose of influenza virus. This vaccine approach has great potential as an alternative vaccination strategy.
Technical Abstract: Protective immunity against avian influenza (AI) virus was elicited in chickens by single dose in ovo vaccination with a replication competent adenovirus (RCA) -free human adenovirus vector (Ad5) encoding an avian AI virus H5 hemagglutinin. Vaccinated chickens were protected against both H5N1 and H5N2 highly pathogenic AI virus challenges. Mass-administration of this AI vaccine can be streamlined with available robotic in ovo injectors. In addition, Ad5-vectored vaccines can be produced rapidly and the safety margin of the non-replicating vector is superior to that of a replicating counterpart. Furthermore, this mode of vaccination is compatible with epidemiological surveys of natural AI infections.