Paul Ehrlich and O.T. Avery; pathfinders in the search for immunity

This paper is concerned with the use of passive immunity for the prevention and treatment of infections from a historic perspective, particularly in regard to the research of Paul Ehrlich on diphtheria and that of O.T. Avery on pneumonia. It is timely to reexamine this matter, particularly in regard to virus infections, in view of the difficulties in developing antiviral drugs. In addition, specific antibodies can serve as an alternative therapy for antibiotic resistant microbes. It is worth recalling in the history of vaccine development that success in passive immunity has been the key element in devising a successful strategy to develop a vaccine to produce humoral immunity.