A CONTRIBUTION TO THE INCREASE OF THE EFFICACY OF KILLED PLAGUE VACCINES. COMMUNICATION II. A NEW PRINCIPLE FOR THE PREPARATION OF DEVITALIZED SUGAR VACCINES,
Abstract
The strains of the plague microbe having full-value immunogenic properties contain a Vi-antigen. The efficacy of killed plague vaccines is determined by the presence and condition of its E- and Vi- antigens. The weak activity of vaccines killed by heat or by the addition of 0.5% phenol is caused by the fact that in these conditions the Vi-antigen disappears completely. In heated sugar vaccines the Vi-antigen is partially retained, and this, in part, explains their superior immunizing properties. Plague vaccine killed in a concentrated solution of sugar without heating, transmits to the most plague-sensitive animals an immunity that by duration and intensity can be compared only to the immunity induced by live vaccine. The high immunogenicity of vaccines prepared according to the new method is made possible by the fact that in it the heat-labile antigens of the plague microbe are minimally altered. In order to produce more effective vaccines it is necessary to select strains according to their content of Vi- and E- antigens. The addition of 0.05% agar to the dilutant liquids increases the efficacy of the killed sugar vaccine. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1968
- Accession Number
- AD0673311
Entities
People
- E. I. Korobkova
Organizations
- United States Army Biological Warfare Laboratories