Malariologists are inclined to some range of opinion as to when the peak of immunity is gained by people who spend their lives in regions where malaria has high endemicity. Perhaps this is partly due to the fact that it is always more convenient and time saving to survey the children who are more apt to be present at home or in the schools. For many years I have personally been interested in the labor index of malaria and I think enough evidence has been assembled in some regions where I have had service to present it for analysis. It might be well to refer to a few of the records from well recognized authors from 1922 to 1942 before presenting this experience.
(1)Byam and Archibald (1922). Immunity to malaria, when it is present, is almost always a partial immunity acquired by frequent infection and reinfection repeated continuously over a number of years.