THE PRESENT STATUS OF FIELD AND LABORATORY STUDIES OF TYPHOID AND PARATYPHOID VACCINES WITH SPECIAL REFERENCE TO STUDIES SPONSORED BY WORLD HEALTH ORGANIZATION.

The authors present a summary of the information yielded by a number of collaborative field and laboratory studies of typhoid vaccines conducted under the auspices of the World Health Organization, comparing, in particular, the results of various controlled field trials carried out in British Guiana, Poland, the USSR and Yugoslavia, and attempting to evaluate the effectiveness of the vaccines in man.Acetone-inactivated typhoid vaccine, which has been established as an international reference preparation, has been proved in field trials to be of a high degree of effectiveness and to confer protection of long duration.Comparison of the results of the field trials with those of laboratory studies indicate that further research is needed in order to develop a test or tests the results of which can be fully correlated with the effectiveness of typhoid vaccines as demonstrated in man.Reference is also made to field studies of paratyphoid vaccines.