Effects of low pathogenicity avian influenza on turkey breeding flocks and immune evaluation of an H1N2 DNA vaccine

Abstract

Low pathogenicity avian influenza (LPAI) viruses can have substantial negative effects on egg production in turkey breeding flocks. Despite vaccination, turkey breeding hens continue to face disease associated with LPAI. Additionally, detecting a measurable immune response post-vaccination using traditional IAV killed vaccines has been challenging. In the present study, a plasmid-based DNA vaccine expressing the HA gene of an H1N2 LPAI virus in addition with immunostimulatory genes was developed and evaluated in turkeys. Turkeys were challenged with an H1N2 virus to determine the protective efficacy of the vaccine. Virus was neither detected in the birds post challenge by RT-PCR of oropharyngeal swabs nor were antibodies detected by ELISA from their sera. In conclusion, our study suggests DNA vaccine technology may be a good alternative to the currently administered autogenous vaccine, but due to the lack of a challenge model we were unable to properly evaluate immune efficacy of the vaccine.