A radical change in our thinking in regard to BCG vaccination has been initiated by the United States Public Health Service under the guidance of Dr. Herman E. Hilleboe, one time Assistant Surgeon General, with the approval of Surgeon General Thomas Parran. Under the auspices of the United States Public Health Service, a conference on BCG was held in Washington on Sept. 7, 1946.1 This representative body, composed of proponents and opponents of BCG vaccination, concluded and recommended essentially as follows: "A. Medical literature fails to reveal any proven cases of progressive disease as a result of BCG vaccination. B. From studies presented at the conference, it appears that BCG vaccination confers increased resistance to tuberculosis for the limited period of time covered in these studies. C. Extensive investigations should be carried on cooperatively with recognized research groups throughout the country during the coming years, especially in population groups