(a) Their first group numbered 4,950 persons in quarantine at the Naval Training Station. The quarantine was maintained for 24 days, and no influenza appeared during that time. Three thousand five hundred and fourteen of them were released at a time when there were still 200 to 300 cases of influenza being reported daily in San Francisco. Out of the 3,514 men, 15 had influenza, and there were no deaths. (b) At the Mare Island Navy Yards 1,950 marines were released immediately after completion of the inoculation. They were turned into Valejo and San Francisco, where influenza was at its height. Only 35 cases, with 1 death, occurred, and these developed shortly after the men were released in San Francisco. This group was controlled with an unvaccinated group of 8,232 persons who remained at Mare Island, and 1,296 cases of influenza, with 65 deaths, occurred among the controls. (c) At San Pedro 3,100 were vaccinated, and of these 53 had influenza, and there were no deaths. The occurrence among these was compared with the prevalence of the disease in Los Angeles, but this part of the report leaves much to be desired in the way of the relative dates, etc. (d) The fourth group, consisting of 1,080 civilians, developed 14 cases, with no deaths. However, vaccination of this group was not completed until 21 days after the pandemic had appeared in the community. Minaker’s and Irvine’s analyses show a favorable percentage for vaccination in the first two groups, but their groups three and four were not sufficiently well controlled to be of much help. 4. In a report which appeared during October, 1918, Eyer and Lowe (29) published the results of prophylactic inoculation of 1,000 New Zealand troops with a mixed catarrhal vaccine. They controlled their experiments with 19,000 New Zealand troops who were not inoculated. A comparison of the incidence of acute respiratory disease and influenza during the primary wave of the epidemic as it appeared during June and July, gave two cases among the vaccinated troops and an average of 43.2 cases per thousand among the controls. Later they reported (58) the results of much larger experiments as carried out at 17 different camps and hospitals. The vaccine which they used was a typical “mixed” vaccine, save that the authors emphasized the advantage of using strains not more than three generations removed from the body. At some of the camps their reports were unfavorable, but upon the whole their results, as summarized below, were most encouraging. In most instances inoculations were completed just prior to the arrival of the autumn epidemic.