Novel vaccines for use against Actinobacillus pleuropneumoniae are disclosed. The vaccines contain at least one A. pleuropneumoniae transferrin binding protein and/or one A. pleuropneumoniae cytolysin and/or one A. pleuropneumoniae APP4. Also disclosed are DNA sequences encoding these proteins, vectors including these sequences and host cells transformed with these vectors. The vaccines can be used to treat or prevent porcine respiratory infections.
