Others cause few or no clinical signs for many hours, but set off irreversible biochemical processes in minutes or a few hours which lead to severe debilitation or death several days later. Fortunately, some of the most potent bacterial protein toxins act slowly enough that, if they are identified, therapy is usually successful 1224 hours after exposure. It is always better to prevent casualties than to treat injured soldiers. For most of the significant threat toxins in military situations, vaccination is the most effective means of preventing casualties. Immunized laboratory animals are totally protected from high-dose aerosols of these toxins.
Immunization requires a knowledge of the threat, availability of a vaccine, and time.
Some vaccines currently in use require multiple injections, often weeks apart. It may be possible to reduce the time required for immunization. Another approach is being evaluated with current Medical Biological Defense Research Program vaccines. Soldiers could be given a priming dose and the first boost two weeks apart while in basic training. The response generated by the immune system's memory cells might last for many months or even years, although not all soldiers would develop fully protective immunity at that time after two immunizations.