The live attenuated vaccine confers a comprehensive, long-lasting protective immunity in vaccinated animals, yet does not cause disease, according to microbiologist Thomas Inzana. Caused by an organism called Actinobacillus pleuropneumoniae, swine pleuropneumonia can devastate swine herds and is believed to account for millions of dollars a year in production losses.
Victims develop pulmonary lesions, fibrinous adhesions, and pneumonia.
Until now, producers have been forced to use less effective killed vaccines that reduce animal mortality, yet fail to control clinical and sub-clinical infections responsible for diminished weight gain, poor performance, and a carrier state. Since the days of Pasteur, medical researchers have been working on the development of new and improved live vaccines to protect people and animals from many disease-causing bacterial and viral pathogens. It is a vast network that is not fully understood. What is understood, however, has enabled scientists to make remarkable progress in quelling a variety of diseases that threaten human health and well-being and agricultural animal productivity. The white blood cells that flock to the site of an invading pathogenic organism create an inflammatory response that can be damaging in itself.