Short CommunicationRecombinant duck enteritis virus works as a single-dose vaccine in broilers providing rapid protection against H5N1 influenza infection

Although vaccination is an important strategy for controlling H5N1 avian influenza virus infections, broilers (short-lived meat chickens) remain the major victims in disease-endemic countries. Inactivated vaccine usually requires 2-3 weeks to establish solid protection, and recombinant vaccines, including the recombinant fowlpox virus vaccine and the recombinant Newcastle disease virus vaccine are affected by maternal antibodies against the vectors. These disadvantages compromise the protective efficacy of these vaccines in broilers. Here, we evaluated the safety and efficacy of a new recombinant duck enteritis virus that expresses the HA gene of an H5N1 virus (rDEV-re6) in specific-pathogen-free chickens and broilers. We found this new rDEV-re6 virus to be safe in chickens and to induce rapid and solid protection after a single dose. This virus may therefore serve as an ideal single-dose vaccine for broilers.

► H5N1 avian influenza virus is endemic in several developing countries. ► Broilers (meat-chickens) are the major victims of the H5N1 infection in disease-endemic countries. ► We constructed a recombinant duck enteritis virus (DEV) expressing the HA gene of an H5N1 avian influenza virus. ► The recombinant DEV induced rapid and solid protection in broilers against H5N1 challenge after a single dose inoculation.