Influenza

by Warren T. Vaughan

The use of vaccines has been tried. In 1918 it was almost universally begun too late—after the epidemic had become prevalent. Prophylactic vaccination should be inaugurated before the disease actually becomes epidemic. Vaccination, particularly against the secondary invaders, is entirely rational. It may not prevent influenza, but it may protect against the serious complications in individuals and may prevent to an extent the spread of secondary invaders in the community.

Greenwood aptly remarks that, “In estimating the total effects produced upon morbidity and mortality by disease, the non-specific secondary invaders are as important as the specific causes. The camp followers of an army may do more damage than the regular soldiers, and the same camp followers may ravage in the wake of different armies.”

At a conference held at the London War Office, October 14, 1918, the subject of vaccination for influenza was discussed. It was decided that only three organisms should be employed in each case in the preparation of the vaccine; that these races should be recently isolated from cases of the disease developing during the course of the epidemic and that the microorganisms should be submitted to a rigorous study as to race and type. The first dose should include 30,000,000 of Bacillus influenzae, 100,000,000 pneumococcus, 40,000,000 streptococcus; the second dose 60,000,000 Bacillus influenzae, 200,000,000 pneumonococcus, 50,000,000 streptococcus. The vaccine should be sterilized at 55° C. and one-half per cent. phenol should be added. The administration should be at ten days’ intervals.

In the United States the vaccines employed have often contained a greater variety of organisms. It is unnecessary to enumerate the results obtained by various investigators. Some have been mildly enthusiastic, while others have obtained no demonstrable benefit. It will suffice to say that there has been no clear evidence that vaccination has been beneficial, but that the procedure has not been given a thorough trial. If the causative organism of the disease is eventually determined, vaccination will probably be attempted with it as antigen. For the success of vaccination it is important that practically entire communities be inoculated, and that they be so inoculated before the development of epidemic prevalence.

Palliative measures in the presence of an epidemic.—An epidemic, once having obtained a start will run its course. Our attempts will be to lessen its extent and diminish its explosiveness. Or, more probably, we will best succeed by extending the duration and making the invasion less explosive. We must know of its earliest appearance. Notification must be made by physicians to the health authorities in order that the earliest increase may be detected. This again renders the reporting of the disease at all times an essential feature. The administrative control and the publicity to be given have already been discussed.

What general measures should be taken against the disease? Should the public schools be closed? Winslow and Rogers found that the orthodox methods of combating epidemics applied in Connecticut exerted no appreciable influence on the spread of influenza. Bridgeport, Hartford and New Haven did not close their schools and suffered from death rates near the average for the State, lower than the rates which prevailed in cities like New London and Waterbury, which closed their schools. No deductions can be drawn from this fact, however, because the closing of the schools in most cases was forced because of the severity of the outbreak.

The data obtained by Jordan indicate that schools were not important distributing centers for the infection. No explosive outbreak occurred in any one grade, and the four days of the Thanksgiving holiday evidently afforded more favorable opportunities for infection than did the days of regular school attendance.

Carnwath believes that in view mainly of the marked prevalence of the disease amongst school children, the balance of opinion is in favor of closure, even in densely populated urban districts. In the author’s investigation there was a slightly higher incidence of the disease among children attending school than among those younger children who were not at school. The spread is probably not facilitated so much in the class room as it is on the play ground. In the school room the children are constrained to remain at a certain distance from each other. Probably they would come into as close contact with cases if they were not at school. Certainly it has not been demonstrated that the school room is a factor of great importance in the spread of influenza. It would, perhaps, be better not to close the schools in the presence of an epidemic, but to discontinue any congregation on the play grounds, and to discourage the grouping of children in play on the streets.

With children and with all individuals, large or small, a great factor in exposure and probably in the transmission of the disease is the necessary crowding on street cars and in public buildings. Here is a potent source which requires deep study and new treatment. Some cities have with partial success attempted lessening the congestion in public conveyances at the beginning and closing of business hours by arranging with the various offices, stores, etc., that the opening and closing times occur at different hours. In order that this procedure may work it is important that the employees of a factory or store which closes early must ride to their destination at the time of closing and not remain in the congested business districts. Here again it is a problem of educating the public to a point where they will co-operate intelligently.

It has been amply demonstrated that crowd gatherings markedly facilitate the spread of the disease. Mass meetings should be prohibited and gatherings in and out of doors should be discouraged. The public should be taught that the safest place is at home.