Controlled field trial with dried sorbed paratyphoid B and typhoid vaccines.

In 1968-70 a field trial was arranged in the USSR to evaluate the effectiveness of dried sorbed paratyphoid B and typhoid vaccines when administered in two doses separated by an interval of 20-30 days.TWO GROUPS OF SCHOOLCHILDREN WERE UNDER OBSERVATION: a group inoculated with paratyphoid B vaccine (75 805 children) and a group inoculated with typhoid vaccine (76 314 children). The persons who were inoculated with the paratyphoid B vaccine formed the control group used in evaluating the effectiveness of the typhoid vaccine, and those inoculated with the typhoid vaccine formed the control group for the evaluation of the paratyphoid vaccine.

A controlled field trial to evaluate the protective capacity of a single dose of acetone-killed agar-grown and heat-killed broth-grown typhoid vaccines.

In a strictly controlled field trial among schoolchildren a study was made of the protective capacity of single doses of 2 typhoid vaccines: a heat-killed broth-grown sorbed dried vaccine made in the USSR (vaccine G-66) and an acetone-killed agar-grown dried vaccine (vaccine K-66) made in Yugoslavia. The latter vaccine was supplied by the World Health Organization.A single dose of these preparations exerted a statistically significant protective effect during the first 10 months of observation.