Constitutional and non-specific immunity to infection.

Most immunologists focus on elaborate non-specific and antigen-specific factors of reactive immunity produced by the vertebrate lymphoid system. Modern principles of immunogenic prophylaxis and therapy are based solely on the use of these agents. There is, however, a more effective system of specific resistance which is shared by all forms of life: hereditary constitutional immunity to infection and invasion. An explosive growth in knowledge of the constitutional immunogenic system has occurred during the past two decades. The author illustrates the nature and importance of constitutional immunity, using examples from genetics and molecular biology. Special attention is given to testing for genetic susceptibility to infection and genetic engineering of resistance.