Immunity
in medicine the name which it is safe from the attacks of particular infectious germs, or certan poisons. Although the phenomena of immunity occur in cases of several vegetable and animal poisons (ricin, and snake venom for instances) not associated with disease, and are, hence, not strictly limited to the infectious diseases, they are of chief prophylactic and therapeutic interest in connection with the resulted from a preceding attack of yel- a natural insusceptibility, or may have munes.
Their immunity may be due to These persons are spoken of as im- neighbors fall victims to the fever. dividuals remain healthy, while their low fever. One attack of many of the infectious diseases confers immunity These persons are spoken of as imgerm. This fact, long ago noted by the
Their immunity may be due to resulted from munes. low fever. One attack of many of the infectious diseases confers immunity com a preceding attack of yelfrom any further attacks by the same germ. This fact, long ago noted by the medical practitioner (and utilized for the prevention of smallpox in China several hundred years ago), is now being applied in prevention and curative work in the case of many common infectious diseases-typhoid fever, chol cerebrospinal meningitis, munity conferred upon person by an attack of disease is called active; that resulting from an artificial treatment cholera, plague, with vaccines is, etc. The imremedies used in producing artificial immunity are called vaccines, antitoxins or sera, passive. The and toxins. Vaccines usually consist of living or dead bacteria or their poisons (toxins); sometimes the living organisms are weakened or attenuated by heat, growth on special culture media, passage through other animals, etc., before use in the human body. The injection of vaccines, in small, frequently repeated doses, stimulates the normal protective agencies of the body. If the special disease germs, for which the vaccine is intended, IMPEACHMENT are present in the body, in other words if the man already has the disease, the body forces, in raising a defensive army. builds up a condition of immunity, so vaccine serves as an aid to the regular that an attack by the germ, if it occurs at a later period, can be warded off.
Vaccines have been more successful as preventives than as cures. nity produced may be permanent and preventives than as cures. The immu- Vaccines have been more successful as If the disease is not present, the vaccine lasting or merely temporary, a few weeks jecting in an animal (horse, goat, dog, which or months. Antitoxins are substances animal's blood finally becomes highly reduced by disease germs. They are comwhich act as antidotes to the toxins pro- The immusistant to this particular organism, and it can withstand without harm many monly manufactured by repeatedly intimes the dose of germs fatal to a similar animal not so artificially immunize which an antitoxin is desired. The the organism or its poisons against etc.), with increasingly virulent doses of jecting in an animal (horse, goat, dog, monly manufactured by repeatedly in- duced by disease germs. They are comportion of the blood of the immunized the organism or its poisons against it can withstand without harm many from this constitutes the essential elean antitoxin is desired. The ments of the commercial antitoxin. immunized . A to express the thickness of the layer or body of pigment applied by the painter