The principle in such treatment by means of vaccines is to stimulate the general production of anti-substances throughout the body, so that these may be carried to the sites of bacterial growth, and aid the destruction of the organisms by means of the cells of the tissues.
So technology supports quality of life (from vaccines to Volvos) and generates wealth.
It was formerly supposed that the injection of attenuated cultures or dead organisms-vaccines in the widest sensewas only of service in producing immunity as a preventive measure against the corresponding organism, but the work of Sir Almroth Wright has shown that the use of such vaccines may be of service even after infection has occurred, especially when the resulting disease is localized.
In this case a general reaction is stimulated by the vaccine which may aid in the destruction of the invading organisms. In regulating the administration of such vaccines he has introduced the method of observing the opsonic index, to which reference is made below.
Cultures of varying degree of virulence may be obtained by such methods, and immunity can be gradually increased by inoculation with vaccines of increasing virulence.