Session 3 proved to be an important session in which were presented the fundamental data that permit one to conclude that immunization procedures employing attenuated measles virus are effective and practical.
Dr. Enders opened the session with a comprehensive review of information on attenuated strains of measles virus and provided details regarding the derivation and properties of the Edmonston strain.
One of the impressive aspects of the session was the uniformity of experience with the Edmonston B-level strain of attenuated measles when this was administered to children. This was evident from the reports of different groups of investigators working in different geographic areas among people of several racial stocks. The report of Dr. Katz, which compared and contrasted the infections produced in susceptible children by subcutaneous injections of Edmonston B-level attenuated virus and by wild measles virus, was more comprehensive than those of the other speakers who dealt with the