The Logic and History of Passive Immunity and Antibody Therapies.

This volume takes a broad overview of antibody-based therapies prior to and during the COVID pandemic and examines their potential use in future pandemics. Passive antibody therapy was the first effective antimicrobial treatment and its development in the early twentieth century helped catalyze immunological and microbiological research. During the era of serum therapy (1890-1940) antibody-based therapies were developed against both viral and bacterial diseases. Effective treatment required an understanding of how to quantify antibodies, how to develop serotype-specific sera and recognition of the need to treat early in disease. Thus, although the era of serum therapy essentially ended with the development of small molecule antimicrobial therapy in the 1940s, antibody-based therapies led to important new scientific understanding, while remaining in use for some toxin and venom-caused diseases and in the prevention of outbreaks of viral hepatitis. A renewed interest in antibody-based therapies was seen in the widespread deployment of convalescent plasma and monoclonal antibodies during the COVID-19 pandemic. Convalescent plasma will likely be the first specific therapy during outbreaks with new pathogens for which there is no other therapy. For all forms of antibody-based therapies, effectiveness relies on the key principles of antibody therapy, namely, treatment early in disease with preparations containing sufficient antibody specific to the microbe in question.