| 摘要 |
<p>A vaccine against a microbial pathogen comprised of a live, immunogenic but prototrophic and avirulent mutant strain of the selected microbial pathogen in an amount effective to confere immunity. A method of obtaining a vaccine that induces a heightened cellular and humoral immune response to one of a variety of microbial pathogens in a warm blooded animal. A method for isolation of an avirulent strain of a selected pathogenic microorganism.</p> |
