Salmonella: a new vector for the pneumonia vaccine

Researchers at the Biodesign Institute (Arizona State University) have genetically modified the enteric salmonella bacterium to make it produce an antigen against pneumonia. The bacterium, released into the patient, produces antibody molecules capable of counteracting the pneumonia bacterium without causing damage to the body. “If we try to use live Streptococcus pneumoniae to make a vaccine, we will end up killing the patient. The strong point in using the "live" vaccine, in a form of Salmonella that is harmless to humans, is that the bacterium is absorbed from the intestine where it causes an immune reaction, producing a small part of Streptococcus pneumoniae, which in itself it's not lethal." That's according to Roy Curtiss, director of the Biodesign Institute's center for infectious diseases, who took part in the research. In the experiments conducted, the modified Salmonella colonizes the host's lymphatic tissue where it produces Streptococcus pneumoniae proteins, which in turn trigger a strong production of antibodies. The great advantage of a bacterium capable of producing the vaccine considerably lowers the costs of immunization. [ more info | photo ]