Comparative study of reactions and serological response to cholera vaccines in a controlled field trial conducted in the USSR.

This article presents the results of a comparative study of the reactogenicity and the serological response induced by a number of cholera vaccines. Conducted in the USSR on 998 adults aged 18 years and over, the study covered whole-cell heat-killed and formalin-inactivated cholera vaccines, whole-cell heat-killed El Tor vaccine, and a new partially purified toxoid preparation proposed for the immunoprophylaxis of cholera-all administered by hypodermic syringe or jet injector. The most marked reactions were found to occur with the formalin-inactivated cholera vaccine and the least marked with the partially purified toxoid. It was also established that the toxoid was no less effective than the whole-cell vaccine in inducing the intense production of antibodies to the Inaba serotype and, in somewhat lesser degree, to the Ogawa serotype of the El Tor vibrio. It was the only preparation to give rise to intense production of specific antitoxins in 95-98% of cases. The reactions to and immunogenic properties of the cholera vaccines did not show any statistically significant difference whether administered by hypodermic syringe or by jet injector.

Clinical studies of the use of bacteriophage in the treatment of cholera.

This study reports the use of bacteriophage prepared in the USSR in the treatment of cholera. Patients with acute cholera were rehydrated with a standard intravenous solution and were then given a bacteriophage preparation in addition to maintenance intravenous therapy. The titre of the phage preparations was between 10(8) and 10(9) pfu/ml. Bacteriophage was given by mouth (25 ml for adults and 20 ml for children) for 3 days; in addition, some patients were also given an intramuscular injection (20 ml) of phage on the first day in hospital. For comparison, other groups of patients were given a standard tetracycline regimen or a placebo preparation. Daily vibrio and phage counts were made on stool samples from all patients and the vibrio strains isolated from each patient were tested for sensitivity to the phage preparation.The criteria used to evaluate the various therapies were duration of diarrhoea, volume of stool, and duration of vibrio excretion.The results of the study demonstrate that, in the doses used, the therapeutic effect of bacteriophage, if any, was markedly inferior to that of tetracycline and that in the current state of our knowledge bacteriophage, as used in this study, has no place in the treatment of cholera.