THE IMPORTANCE OF THE PLAGUE MICROBE'S CAPSULE IN THE PROBLEM OF LIVE VACCINES
Abstract
Growing plague cultures, including the EV strain, on common media in an atmosphere with an increased carbon dioxide content at 37C contributes to their intensified capsulation. An EV strain grown in the presence of carbon dioxide, long retains the increased capsulation capacity under normal conditions. An EV culture grown under the conditions of an increased content of carbon dioxide at 37C, and having broad capsular dimensions, possesses a greater immunogenic capacity than the same culture grown under ordinary conditions at 20C and having insignificant capsular dimensions. A single vaccination with the large-capsular culture (10 million microbes subcutaneously) transmits to white mice a 75%-100% immunity to 100 lethal doses, and higher, of a virulent strain of the plague microbe, whereas its small-capsular variant, with the same immunizing dose, can protect only 20%-50% of the mice from death. The immunity produced by the large-capsular EV culture is more intense than that created by the small-capsular variant of this strain. A single immunization with this culture (10 million microbes subcutaneously) protects 70%-54.6% of the white mice from such massive doses of a virulent strain as 2500-10,000 Dcl, with the challenge 41 days after immunization. The small-capsular EV culture protects only 10%-18.2% from these doses.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1968
- Accession Number
- AD0838282
Entities
People
- A. D. Garmazova
Organizations
- United States Army Biological Warfare Laboratories