Antibody responses to heat-killed, phenol preserved parenteral typhoid vaccine.

The heat-killed, phenolized parenteral typhoid vaccine was tested in informed volunteers. Assessment for its immunogenicity was performed using Widal test and enzyme-linked immunosorbent assay (ELISA). The anti-H antibody, which is a marker of the vaccine antigenicity peaked at one month after the vaccination and appeared throughout the one year course of the study.