One dose vaccination against Mycoplasma infections of pigs

A method of preparing a one phase aqueous composition comprising a Mycoplasma hyopneumoniae bacterin, an acrylic acid polymer in a concentration range between 0.8 and 1.2 mg/ml, a pharmaceutically acceptable carrier, and substantially no oil;

• comprising:
• a. cultivating a M. hyopneumoniae whole cell culture such that the Mycoplasma hyopneumoniae bacterin has an antigen amount of at least 3 log 10 per ml;
• b. inactivating the M. hyopneumoniae whole cell culture;
• c. isolating an immunizing amount of a Mycoplasma hyopneumoniae bacterin;
• d. admixing an acrylic acid polymer in the concentration range between 0.8 and 1.2 mg/ml;
• and
• e. admixing a pharmaceutically acceptable carrier.