4. The army pneumo-lipovaccine apparently offers some protection against primary infections with types I, II and III pneumococci, and a somewhat lesser amount of protection against secondary pneumococcic infections with these strains following influenza. 5. While it is impossible to say that the large number of influenza cases developing almost immediately after vaccination would not have occurred anyway, it is at least suggestive that a temporary break occurs in the resistance after the inoculation, and that unusual care should be taken by persons who have been recently vaccinated, particularly when they are in the midst of an epidemic disease. PART II. GENERAL PROPHYLACTIC MEASURES One of the most remarkable things about the 1918 pandemic was the great rapidity with which it spread to all parts of the world. From the report of the first cases which landed in Boston until the epidemic arrived in San Francisco the time consumed was less than two months, and the peaks of the two epidemics were just about one month apart. Apparently no part of the world escaped. Asia, Europe, Africa, North and South America, and some of the remote islands of the Pacific, all reported large epidemics, with high mortality and great suffering. The deplorable failure of precautionary measures in controlling the spread, or at least in limiting the disease, may be offset in a measure by the unusual conditions under which almost everybody had been living. Vast numbers from all over the world were gathered together because of the war. Thousands of men were housed together in army camps or in training cantonments. Other thousands were doing relief work or engaged in the manufacture of munitions. Most of those at home were doing double duty, and were on a severe nervous strain. Everyone everywhere was working to the limit and was consequently fatigued. The necessities of war had cut down the amounts of food generally, and sugar and fat rations particularly. Traffic, both between nations and at home, had never been so great nor accommodations so insufficient. So that it is likely that all of these and many more changes in the daily routine of individuals led to a condition of lowered resistance, and at the same time increased their chances of exposure. One point, at least, stands out prominently, and that is that “influenza as it occurred clinically during the first great wave was different from those cases which appeared later.” This was seen in the acuteness of the onset, in the severity of symptoms, and in the high mortality rate. Therefore, any measure which afforded protection, if only for the time being, is worthy of retrial.