A vaccine composition for birds comprising as an active ingredient a structure containing O-antigen derived from Gram-negative bacteria, provided that said structure does not contain a whole cell, and a process for preparing the same are provided. By using a structure containing O-antigen (e.g. lipopolysaccharide) derived from Gram-negative bacteria as an active ingredient in accordance with the present invention, alleviation of inoculation reaction and reduction in an amount of injection are attained as compared to the conventional whole-cells vaccine to thereby allow for the increase in the number of other antigens to be mixed therewith.
1. A composition comprising lipopolysaccharide from Salmonella,
wherein the Salmonella is one or more Salmonella groups selected from the group consisting of O4, O7 and O9, and
wherein the composition comprises at least one purified lipopolysaccharide O-antigen from Salmonella Enteritidis, Salmonella Typhimurium , and Salmonella Infantis , provided that said O-antigen is not comprised in a whole cell.
2. The composition of claim 1 , further comprising at least one of an antigen from Newcastle disease virus, an antigen from avian infectious bronchitis virus, an antigen from Mycoplasma gallisepticum , an antigen from Egg drop syndrome virus, or an antigen from Haemophilus paragallinarum.
3. The composition of claim 1 , comprising the O-antigen in an amount of at least 5,400 EU/ml.
4. The composition of claim 1 , comprising the O-antigen in an amount of at least 54,000 EU/ml.
5. The composition of claim 1 , comprising two of the purified lipopolysaccharide O-antigens.
6. The composition of claim 1 , comprising three of the purified lipopolysaccharide O-antigens.
7. The composition of claim 1 , further comprising an adjuvant.
8. The composition of claim 1 , wherein the O-antigen is not bound to a carrier protein.
9. The composition of claim 1 , wherein the O-antigen is bound to a carrier protein.
10. The composition of claim 9 , wherein the carrier protein is selected from the group consisting of diphtheria toxoid (DT), tetanus toxoid (TT), cholera toxin (CT) and CRM197.