This result is further evidence that prion replication does not require genetic information. Transmission
It has been recognized that prion diseases can arise in three different ways: acquired, familial, or sporadic. It is often assumed that the diseased form directly interacts with the normal form to make it rearrange its structure. One idea, the "Protein X" hypothesis, is that an as-yet unidentified cellular protein (Protein X) enables the conversion of PrPC to PrPSc by bringing a molecule of each of the two together into a complex.The primary method of infection in animals is through ingestion. It is thought that prions may be deposited in the environment through the remains of dead animals and via urine, saliva, and other body fluids. They may then linger in the soil by binding to clay and other minerals.A University of California research team has provided evidence for the theory that infection can occur from prions in manure. And, since manure is present in many areas surrounding water reservoirs, as well as used on many crop fields, it raises the possibility of widespread transmission. It was reported in January 2011 that researchers had discovered prions spreading through airborne transmission on aerosol particles, in an animal testing experiment focusing on scrapie infection in laboratory mice. Preliminary evidence supporting the notion that prions can be transmitted through use of urine-derived human menopausal gonadotropin, administered for the treatment of infertility, was published in 2011.
Vaccine
No licensed vaccines are available.An early attempt to create a scrub typhus vaccine occurred in the United Kingdom in 1937 (with the Wellcome Foundation infecting around 300,000 cotton rats  in a classified project called "Operation Tyburn"), but the vaccine was not used. The first known batch of scrub typhus vaccine actually used to inoculate human subjects was dispatched to India for use by Allied Land Forces, South-East Asia Command in June 1945. By December 1945, 268,000 cc had been dispatched. The vaccine was produced at Wellcomes laboratory at Ely Grange, Frant, Sussex. An attempt to verify the efficacy of the vaccine by using a placebo group for comparison was vetoed by the military commanders, who objected to the experiment.Enormous antigenic variation in Orientia tsutsugamushi strains is now recognized, and immunity to one strain does not confer immunity to another. Any scrub typhus vaccine should give protection to all the strains present locally, to give an acceptable level of protection. A vaccine developed for one locality may not be protective in another, because of antigenic variation. This complexity continues to hamper efforts to produce a viable vaccine.Dora Lush, an Australian bacterioloigist, died after accidentally pricking her finger with a needle containing scrub typhus while inoculating a mouse in an attempt to develop a vaccine. History
Severe epidemics of the disease occurred among troops in Burma and Ceylon during World War II.