BCG vaccine bacilli that seemed less virulent, and changed the course of their research to see if repeated subculturing would produce a strain that was attenuated enough to be considered for use as a vaccine. The BCG strain was isolated after subculturing 239 times during 13 years from virulent strain on glycerine potato medium. The research continued throughout World War I until 1919, when the now avirulent bacilli were unable to cause tuberculosis disease in research animals. Calmette and Guerin transferred to the Paris Pasteur Institute in 1919. The BCG vaccine was first used in humans in 1921. Public acceptance was slow,
Inoculation theory message acceptance and source credibility. This study is relevant to inoculation research in that it lends credence to Miller, et al. (2013), which transparently incorporates psychological reactance theory in conjunction with inoculation theory to improve the quality of persuasive appeals in the future. Following Compton and Pfau's (2009) research on postinoculation talk, Ivanov, et al. (2012) explore how cognitive processing could lead to talk with others after receiving an inoculation message in which threat exists. The authors found that message processing leads to postinoculation talk which could potentially lead to stronger resistance to attack messages. Further, postinoculation talk acts virally,