STUDY OF EFFICACY OF TYPHOID VACCINE IN INDUCING HUMORAL AND CELL-MEDIATED IMMUNE-RESPONSES IN HUMAN VOLUNTEERS

  • 1 January 1977
    • journal article
    • research article
    • Vol. 30  (1) , 38-43
Abstract
The nature of protective immunity against typhoid fever in man is not (at present) well understood. Work on animal models and earlier studies indicate an important protective role for cellular immunity. The present work attempts to study the efficacy of the conventional typhoid vaccine in inducing specific cellular and humoral immune responses. The study on 58 new army recruits and 31 civilian volunteers showed adequate humoral responses after vaccination. Vaccination failed to induce a significant cellular immune response. A transient suppression of cellular immunity was observed in the immediate post-vaccination period in 10 subjects who possessed natural cellular immunity before vaccination. These findings indicate the need for improving the typhoid vaccine so that it will induce cellular immunity as well as a humoral response. It is important to obtain detailed knowledge of the post-vaccination anergy as this could be important in timing public health programs.