Live vaccines and methods of treatment therewith

A method of producing protective immunity against Newcastle disease in a chicken, comprising:

• (a) administering to a chicken during the last half of in ovo incubation a composition comprising a vaccine comprising a live pathogenic Newcastle disease virus;
• and
• (b) administering to a chicken during the last half of in ovo incubation a composition comprising a Type I interferon;
• wherein the live pathogenic virus is administered in an amount effective to produce an immune response in the chicken;
• and
• wherein the Type I interferon is administered in an amount effective to (1) reduce the pathology that would occur in the absence of the Type I interferon due to the administration of the vaccine, and (2) allow the production of a protective immune response in the chicken.

A method of reducing mortality from the administration of a live vaccine virus in ovo to an avian subject, comprising:

• (a) administering to an avian subject in ovo a composition comprising a vaccine comprising a live vaccine virus;
• and
• (b) administering to the avian subject in ovo a composition comprising interferon;
• wherein the live vaccine virus is administered in an amount effective to produce an immune response in the avian subject;
• and
• wherein the interferon is administered in an amount effective to (1) reduce the pathology that would occur in the absence of the interferon due to the administration of the vaccine, and (2) allow the production of a protective immune response in the avian subject.

A method of producing protective immunity against a viral disease in an avian subject, comprising:

• (a) administering to an avian subject in ovo a composition comprising a vaccine comprising a live pathogenic virus;
• and
• (b) administering to the avian subject in ovo a composition comprising about 1 μg to about 80 μg of a Type I interferon, said Type I interferon having a specific activity of 1×105 to 1×108 units per milligram;
• wherein the live pathogenic virus is administered in an amount effective to produce an immune response in the avian subject;
• and
• wherein the interferon is administered in an amount effective to (1) reduce the pathology that would occur in the absence of the interferon due to the administration of the vaccine, and (2) allow the production of a protective immune response in the avian subject.

A method of reducing mortality from the administration of a live vaccine virus in ovo to an avian subject, comprising:

• (a) administering to an avian subject in ovo a composition comprising a vaccine comprising a live vaccine virus;
• and
• (b) administering to the avian subject in ovo a composition comprising about 10 μg to about 40 μg of a Type I interferon, said Type I interferon having a specific activity of 1×105 to 1×108 units per milligram;
• wherein the live vaccine virus is administered in an amount effective to produce an immune response in the avian subject and an amount effective to produce mortality in the absence of the interferon;
• and
• wherein the interferon is administered in an amount effective to (1) reduce the pathology that would occur in the absence of the interferon due to the administration of the vaccine, and (2) allow the production of a protective immune response in the avian subject.

A method of producing protective immunity against Newcastle disease in a chicken, comprising:

• (a) administering to a chicken during the last half of in ovo incubation a composition comprising a vaccine comprising about a 10−2 EID50to about a 106 EID50 dose of a live pathogenic Newcastle disease virus;
• and
• (b) administering to a chicken during the last half of in ovo incubation a composition about 10 μg to about 40 μg of a Type I interferon, said Type I interferon having a specific activity of 1×105 to 1×108 units per milligram;
• wherein the live pathogenic virus is administered in an amount effective to produce an immune response in the chicken;
• and
• wherein the Type I interferon is administered in an amount effective to (1) reduce the pathology that would occur in the absence of the Type I interferon due to the administration of the vaccine, and (2) allow the production of a protective immune response in the chicken.

A method of producing protective immunity against a pathogenic viral disease in an avian subject, comprising:

• (a) administering to an avian subject in ovo a composition comprising a vaccine comprising a live pathogenic virus;
• and
• (b) administering to the avian subject in ovo a composition comprising interferon;
• wherein the live pathogenic virus is administered in an amount effective to produce an immune response in the avian subject and in an amount sufficient to cause at least about a 30% decrease in hatch rate in specific pathogen free avian subjects in the absence of the interferon;
• and
• wherein the interferon is administered in an amount effective to (1) reduce the pathology that would occur in the absence of the interferon due to the administration of the vaccine, and (2) allow the production of a protective immune response in the avian subject.