I. Break the channels of communication by which the infective agent passes from one person to another.
II. Render persons exposed to infection immune, or at least more resistant, by the use of vaccines.
III. Increase the natural resistance of persons exposed to the disease, by augmented healthfulness.
I. Breaking the channels of communication.
(a) By preventing droplet infection. The evidence offered indicates that this is of prime importance.
(b) By sputum control. The evidence offered indicates that the danger here is due chiefly to contamination of the hands and common eating and drinking utensils.
(c) By supervision of food and drink. Evidence offered does not indicate much danger of infection through these channels.
Details and practical methods possible for the limitation of infection through droplets, sputum, and food and drink are discussed later under special preventive methods.
II. Immunization and vaccines.
(See the report of the laboratory committee appended.)