Duration of Immunity Conferred by Typhoid Vaccine: Results of Re-vaccination by Intracutaneous Injection of Typhoid Vaccine

Abstract

This work was done by the Laboratory Staff of the Army Medical School. Exptl. evidence based on mouse protection tests indicates that the protective antibodies diminish gradually, commonly persisting, however, for 2 to 4 yrs. In 100 test persons, a single revaccination with an intracut. injection of 0.1 cc. typhoid vaccine (100 million organisms) has caused a return of serum antibodies similar in amt. to those due to a reinjection series of the regular 3 doses. This single intracut. revaccination is manifestly simpler, less time consuming, and gives less severe reactions.