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 of this study is to determine how to improve the effectiveness of the inoculation process by evaluating and generating reactance to a threatened freedom by manipulating explicit and implicit language and its intensity. While most inoculation studies focus on avoiding reactance, or at the very least, minimizing the impact of reactance on behaviors, in contrast, Miller, et al. (2013) chose to manipulate reactance by designing messages to enhance resistance and counterarguing output. They posit seven hypotheses in this study. H1 aims to discover if reactance-enhanced messages warning of a potential attitudinal threat negative affect and cognitions toward the attack message