Abstract: The present invention provides methods of inducing an immune response against Clostridium species in birds, for protecting birds from Clostridium infection, and/or for protecting birds from related disorders such as necrotic enteritis. The methods can be practiced in ovo and/or post-hatch. The invention further provides compositions and methods for delivery of a composition of this invention in ovo directly to the embryo body.

Abstract: The present invention provides methods of inducing an immune response against Clostridium species in birds, for protecting birds from Clostridium infection, and/or for protecting birds from related disorders such as necrotic enteritis. The methods can be practiced in ovo and/or post-hatch. The invention further provides compositions and methods for delivery of a composition of this invention in ovo directly to the embryo body.

Abstract: Disclosed herein are methods and pharmaceutical formulations for administering vaccines to birds. In preferred embodiments, the invention provides methods of administering live pathogenic virus vaccines to birds in ovo, more preferably, during the last quarter of in ovo incubation. Interferon, more preferably, Type I interferon, may be advantageously administered in conjunction with live virus vaccines to decrease the pathogenicity thereof. Interferon must be provided at doses sufficient to protect against pathogenicity of the live vaccine, but not at doses so high as to prevent the host from mounting an active immune response. Further provided are pharmaceutical formulations comprising effective doses of live vaccine and interferon. Finally, the present invention provides methods of administering interferon together with live vaccines to young avians to effectively overcome the interfering effects of maternal antibodies.