Immunology: from books and bench to bedside

The time has passed when immunology was just another basic science discipline in the first years of medical school that students needed to memorize enough to pass examinations and not to worry much thereafter depending on the specialty pursued. Nowadays, the understanding of immunological mechanisms is increasingly essential in many disciplines because most diseases have a component of inflammatory response along side the inciting agent as part of the pathogenesis of their clinical manifestations and also as part of tissue repair from damage. Besides the involvement of the immune system in diseases of other organ systems, many new immunological diseases have been recognized from deficient, exaggerated and misdirected immunological responses. The detailed knowledge of immunological mechanism of disease pathogenesis down to molecular mechanisms has been possible because of the tremendous advances in basic immunology and application of that knowledge and tools to patients. Immunology-based therapies account for major advances in medicine (Table 1). Over a century ago when immunology was in its birth, scientists were already using killed microbes as vaccines and heterologous antibodies as antidotes. Despite rudimentary knowledge of the mechanisms of those treatments, physicians had remarkable successes and many of those treatments are still used today in refined forms. Killed microbes or parts of them are used in vaccines, which are highly successful to prevent infectious. Indeed, vaccines are the most important advance in medicine for its role in markedly preventing morbidity and mortality worldwide, particularly in children, caused by infectious diseases including poliomyelitis, measles, mumps, diphtheria, tetanus, varicella, influenza, hepatitis A and B, yellow fever, rabies and invasive bacterial infections caused by Haemophilus influenzae, meningococci and Streptococcus pneumoniae. Still, enormous challenges lie ahead such as malaria, tuberculosis and HIV infection. Since 1911, vaccines have also been successful in secondary prevention of symptoms in already established disease as in the case of IgE-mediated hypersensitivity respiratory allergies, and later, insect anaphylaxis. Vaccines prime the immune system to respond to infectious agents so that when an infection occurs, it elicits a fast and intense memory immune response that clears the infection. In the case of allergic diseases, vaccines modify the exaggerated hypersensitivity immune response to an attenuated and less damaging response.