2016-08-242016-08-242001-12-04http://hdl.handle.net/10919/72442Vaccines for diseases caused by normally encapsulated organisms are produced by genetically modifying those organisms by deleting the genes encoding for capsule synthesis or a portion thereof sufficient to produce non-capsulated mutants of the organisms. As an example, a live, attenuated strain of Actinobacillus pleuropneumoniae genetically modified with a large deletion in a chromosomal regions of the DNA which encodes for capsule synthesis is a safe and effective vaccine against swine pleuropneumonia.application/pdfen-USPatenthttp://pimg-fpiw.uspto.gov/fdd/01/260/063/0.pdf9115824424/93.4424/93.2435/252.3435/440435/471A61K39/0002A61K39/102A61K2039/522A61K2039/552C07K14/285Y10S424/8256326001