The present study is directed largely to questions of immunologic type in dengue fever, and the bearing they have to any kinship with other affections. We encountered that puzzling aspect of the condition's immunity while considering the relation with yellow fever. With it in mind we have gone over the literature of the general immunity in dengue, and add an analysis of former situations at Galveston. Epidemics giving rise to those situations are the same ones, for the most part, that Levy (1923) cited as having spread through Texas in 1897, 1907, 1908, 1912, 1918 and 1922. We have availed ourselves of the kindly proffered collaboration of the Laboratories of the International Health Division of the Rockefeller Foundation, New York, and also of information and blood samples contributed by inhabitants of Galveston and local records.
The only immunologic methods that have proved applicable to dengue investigations are some involving protection from attack.