Title:  Live in ovo vaccine

United States Patent:  6,231,871

Assignee:  American Cyanamid Company (Madison, NJ)

Filed:  May 6, 1996

The present invention relates generally to modified microorganisms suitable for use as live in ovo vaccines for avian species. The live in ovo vaccines of the present invention are useful for inducing immunity before or immediately after hatching against a virulent form of the modified microorganism or a microorganism immunologically related to the modified microorganism or a virulent organism or virus carrying an antigenic determinant expressed by the modified microorganism in the live vaccine. The subject live in ovo vaccines are particularly efficacious in enhancing the survival rate of newly-hatched poultry birds.

SUMMARY OF THE INVENTION

Accordingly, one aspect of the present invention provides a live in ovo vaccine for avian species comprising an attenuated microorganism which:

(a) exhibits auxotrophy to one or more growth factors, such that it is incapable of growing on a minimal medium in the absence of said one or more growth factors;

(b) is capable of colonizing one or more tissues in an embryo prior to hatching; and

(c) is capable of inducing before or immediately after hatching an immune response in the embryo against a virulent form of said microorganism or an immunologically cross-reactive microorganism or a virulent organism or virus carrying an antigenic determinant expressed by said attenuated microorganism.

Another aspect of the present invention contemplates a live in ovo vaccine for poultry birds comprising an attenuated Salmonella which:

(a) exhibits auxotrophy for one or more growth factors such that it is incapable of growing on a minimal medium in the absence of said one or more growth factors;

(b) is capable of colonizing one or more tissues in an embryo prior to hatching; and

(c) is capable of inducing before or immediately after hatching an immune response in the embryo against a virulent form of said Salmonella or an immunologically cross-reactive Salmonella or a virulent organism or virus carrying an antigenic determinant expressed by said avirulent Salmonella.

Yet another aspect of the present invention is directed to a method for immunizing an avian species against infection by a pathogenic microorganism said method comprising administering in ovo an attenuated microorganism which:

(a) exhibits auxotrophy to one or more growth factors such that it is incapable of growing on a minimal medium in the absence of said one or more growth factors; and

(b) is capable of colonizing one or more tissues in an embryo prior to hatching in an amount and under conditions effective to induce an immune response in the embryo before or immediately after hatching against a virulent form of said attenuated microorganism or an immunologically cross-reactive microorganism or virulent organism or virus carrying an antigenic determinant expressed by said attenuated microorganism.

Still yet another aspect of the present invention relates to a method for immunizing poultry birds against infection by a pathogenic microorganism said method comprising in ovo administration of a vaccine comprising an attenuated Salmonella which:

(a) exhibits auxotrophy to one or more growth factors such that it is incapable of growing on a minimal medium in the absence of said one or more growth factors; and

(b) is capable of colonizing one or more tissues in an embryo prior to hatching in an amount and under conditions effective to induce an immune response in the embryo before or immediately after hatching against a virulent form of said Salmonella or a virulent organism or virus carrying an antigenic determinant expressed by said attenuated Salmonella.

Another aspect of the present invention contemplates a fertilized egg from a poultry bird having an air sac wherein the air sac is inoculated with a modified microorganism which:

(a) exhibits auxotrophy to one or more growth factors such that it is incapable of growing on a minimal medium in the absence of said one or more growth factors; and

(b) is capable of colonizing one or more tissues in an embryo prior to hatching after the embryo breaks through the air sac; and

(c) is capable of inducing an immune response in the embryo before or immediately after hatching against a virulent form of said microorganism or an immunologically cross-reactive microorganism or virulent organism or virus carrying an antigenic determinant expressed by said avirulent microorganism.

Claim 1 of 26 Claims

What is claimed is:

1. A method for immunizing an avian species against infection by a pathogenic Salmonella microorganism, said method comprising administering in ovo to an air sac of an egg an attenuated Salmonella microorganism which:

(a) exhibits auxotrophy to one or more growth factors selected from the group consisting of phenylalanine, tyrosine, tryptophan and para-aminobenzoic acid such that it is incapable of growing on a minimal medium in the absence of said one or more growth factors; and

(b) is capable of colonizing one or more tissues in an embryo prior to hatching in an amount and under conditions effective to induce an immune response in the embryo before or immediately after hatching against a virulent form of said attenuated Salmonella microorganism or a microorganism expressing an immunologically cross-reactive antigen.

____________________________________________
If you want to learn more about this patent, please go directly to the U.S. Patent and Trademark Office Web site to access the full patent.