Image Number 18 for United States Patent #5273889.
New chimeric proteins, DNA encoding the same, and the use of these proteins in stimulating immunity against respiratory diseases such as pneumonia, including shipping fever pneumonia, are disclosed. The chimeric proteins include at least one epitope of leukotoxin fused to an active fragment of a cytokine. The chimeric proteins can be used in a vaccine composition. Also disclosed are methods of vaccination as well as methods of making the proteins employed in the vaccines.