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 When McGuire (1966a) created this theory, it was applied to social clichés. This meant it was primarily used toward the attitudes that were rarely, if ever attacked by opposing forces. The early tests of inoculation theory were used on non-controversial issues, (e.g. brushing your teeth is good for you). Few refute that brushing one's teeth is a good habit, therefore external opposing arguments against tooth brushing would not change one's opinion, but it would strengthen support for brushing one's teeth (Banas & Rains, 2010). Inoculation theory studies currently target less popular or common attitudes, such as whether one should buy