FIG. 5.

Onset of clinical immunity to falciparum malaria in a second experimental challenge with homologous versus heterologous strains. Solid bars show the percent reduction in number of days with greater than 1,000 parasites per μl after challenge with a homologous (left, data from 14 human subjects) or heterologous (right, data from 5 human subjects) strain. Gray bars show the percent reduction in mean number of days with a fever higher than 100°F. Light bars show the same for a fever higher than 102°F. (Based on data from reference 243.)