Abstract: A method of producing active immunity against a bacterial or protozoal disease in a subject comprises administering to the subject a vaccine conjugate comprising a live bacteria or protozoa and a neutralizing factor bound to the live bacteria or protozoa. The neutralizing factor is selected from the group consisting of antibodies and antibody fragments. The live bacteria or protozoa is one capable of producing disease in the subject, and the antibody or antibody fragment is one capable of neutralizing the live bacteria or protozoa.

Abstract: A method of producing active immunity against a bacterial or protozoal disease in a subject comprises administering to the subject a vaccine conjugate comprising a live bacteria or protozoa and a neutralizing factor bound to the live bacteria or protozoa. The neutralizing factor is selected from the group consisting of antibodies and antibody fragments. The live bacteria or protozoa is one capable of producing disease in the subject, and the antibody or antibody fragment is one capable of neutralizing the live bacteria or protozoa.

Abstract: A method of producing active immunity against a bacterial or protozoal disease in a subject comprises administering to the subject a vaccine conjugate comprising a live bacteria or protozoa and a neutralizing factor bound to the live bacteria or protozoa. The neutralizing factor is selected from the group consisting of antibodies and antibody fragments. The live bacteria or protozoa is one capable of producing disease in the subject, and the antibody or antibody fragment is one capable of neutralizing the live bacteria or protozoa.

Abstract: A method of producing active immunity against a bacterial or protozoal disease in a subject comprises administering to the subject a vaccine conjugate comprising a live bacteria or protozoa and a neutralizing factor bound to the live bacteria or protozoa. The neutralizing factor is selected from the group consisting of antibodies and antibody fragments. The live bacteria or protozoa is one capable of producing disease in the subject, and the antibody or antibody fragment is one capable of neutralizing the live bacteria or protozoa.

Abstract: A method of producing active immunity against a viral disease in an animal subject comprises administering to the subject a vaccine conjugate consisting essentially of a live virus and a neutralizing factor bound to the live virus. The neutralizing factor is selected from the group consisting of antibodies and antibody fragments. The live virus is one capable of producing disease in the subject, and the antibody or antibody fragment is one capable of neutralizing the live virus. Preferred subjects are birds, a preferred virus is Infectious Bursal Disease Virus, and a preferred route of administration to birds is by in ovo administration.

Abstract: A method of producing active immunity against a viral disease in an animal subject comprises administering to the subject a vaccine conjugate consisting essentially of a live virus and a neutralizing factor bound to the live virus. The neutralizing factor is selected from the group consisting of antibodies and antibody fragments. The live virus is one capable of producing disease in the subject, and the antibody or antibody fragment is one capable of neutralizing the live virus. Preferred subjects are birds, a preferred virus is Infectious Bursal Disease Virus, and a preferred route of administration to birds is by in ovo administration.

Abstract: A method of producing active immunity against a viral disease in an animal subject comprises administering to the subject a vaccine conjugate consisting essentially of a live virus and a neutralizing factor bound to the live virus. The neutralizing factor is selected from the group consisting of antibodies and antibody fragments. The live virus is one capable of producing disease in the subject, and the antibody or antibody fragment is one capable of neutralizing the live virus. Preferred subjects are birds, a preferred virus is Infectious Bursal Disease Virus, and a preferred route of administration to birds is by in ovo administration.

Abstract: A method of producing active immunity against infectious bursal disease virus in an avian subject comprises administering to the subject a vaccine complex consisting essentially of a live virus and a neutralizing factor bound to the live virus. The neutralizing factor is selected from the group consisting of antibodies and antibody fragments. The live virus is one capable of producing disease in the subject, and the antibody or antibody fragment is one capable of neutralizing the live virus. A preferred route of administration to birds is by in ovo administration.

Abstract: A method of producing active immunity against a viral disease in an animal subject comprises administering to the subject a vaccine complex consisting essentially of a live virus and a neutralizing factor bound to the live virus. The neutralizing factor is selected from the group consisting of antibodies and antibody fragments. The live virus is one capable of producing disease in the subject, and the antibody or antibody fragment is one capable of neutralizing the live virus. Preferred subjects are birds, a preferred virus is Infectious Bursal Disease Virus, and a preferred route of administration to birds is by in ovo administration.

Abstract: The present invention provides a low molecular weight anti-viral factors isolated from the serum of a hyperimmune regressor line chicken and methods of purifying same. The factors are useful in the treatment and prevention of certain disease states.