Fowl cholera: protection against Pasteurella multocida by ribosome-lipopolysaccharide vaccine

Ribosomal protein from Aspergillus fumigatus substituted for intact ribosomes in potentiating the immunogenicity of Pasteurella multocida lipopolysaccharide. Ribosomal protein behaved as a carrier for the lipopolysaccharide. The basic protein methylated albumin, but not protamine sulfate, substituted for ribosomal protein as a carrier for lipopolysaccharide. Synthetic single- and double-stranded polynucleotides did not function as an adjuvant to potentiate the immunogenicity of lipopolysaccharide or methylated albumin-lipopolysaccharide complexes. Double-stranded polynucleotide (poly A:poly U), added as an adjuvant for methylated albumin-lipopolysaccharide vaccine, produced sera with lowered passive hemagglutination antibodies to lipopolysaccharide, but it did not influence protection against challenge with P. multocida. No differences in protection were observed between different lines of specific-pathogen-free white leghorn chickens given ribosome-lipopolysaccharide vaccine. Humoral protection, demonstrated by passive-protection tests, was induced by ribosome-lipopolysaccharide vaccine. Cell-mediated immunity was not detected by delayed-type hypersensitivity skin test reactions.