We had found previously that children with ragweed hay fever were somewhat less symptomatic after preseasonal immunization with large doses of ragweed pollen extract than were placebo-treated children. To study further the immunologic changes which accompany immunotherapy, these children were treated again the following year. Each patient served as his own control.
D. A. Levy, L. M. Lichtenstein, E. O. Goldstein, K. Ishizaka