Immunomodulators in infectious diseases: panoply of possibilites.

Infections which caused ravages in the past centuries are again resurgent and newly emerging pathogens capable of human diseases continue to surface. Multidrug antibiotic resistance has turned into a major medical problem. Judicious concepts for combating infections in the 21st century have acquired a new poignancy. Immunomodulators of natural, synthetic, and recombinant origin can stimulate host defense mechanisms for the prophylaxis and treatment of diverse viral, bacterial, parasitic and fungal diseases. Some immunomodulator preparations are already licensed for use in patients and numerous others are being extensively investigated in preclinical and clinical studies. Immunomodulators offer a novel adjunct to established antimicrobial therapies.