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 well as increasing the likelihood that talk will generate a potentially viral effect–spreading inoculation to others through the act of vocal talk (Ivanov et al., 2012). Inoculation theory Inoculation theory was developed by social psychologist William J. McGuire in 1961 to explain how attitudes and beliefs change, and more importantly, how to keep existing attitudes and beliefs consistent in the face of attempts to change them. Inoculation theory functions as a strategy to protect attitudes from change–to confer resistance to counter-attitudinal influences, whether such influences take the form of direct attacks or sustained pressures. The theory posits that weak counterarguments–arguments