Haemophilus parasuis vaccines.

Glässer's disease, which is caused by Haemophilus parasuis, is a major threat to swine throughout the world. At present, the predominant method of controlling this disease is through vaccination with an inactivated vaccine, which has many limitations. For example, there is no available method to differentiate between infected and vaccinated animals. In addition, inactivated vaccines do not contain all of the virulent serovars that circulate in a region. Additionally, novel vaccines that address the shortcomings of inactivated vaccines are not available. Here, we summarize existing knowledge concerning H. parasuis vaccines, and provide some suggestions that may help to improve H. parasuis vaccines.