[Perspectives on the Future of Antibody Therapeutic Use for the Prevention and Treatment of Infectious Diseases].

Antibodies are endogenous proteins that are involved in humoral immunity. Although various therapeutic monoclonal antibodies (mAbs) targeting cancer and immune diseases have been widely used, the development of mAbs for the treatment of infectious diseases has remained limited. During the coronavirus disease 2019 (COVID-19) pandemic, various mAbs targeting the spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were developed, received Emergency Use Authorization (EUA), and were used for treating and preventing COVID-19. As successive SARS-CoV-2 variants emerged and the pandemic spread, mAbs with high target specificity proved less effective against these variants. Consequently, their EUAs were suspended within a short period, highlighting the limitations of antiviral mAbs developed against emerging infectious diseases. Since 2021, guidance documents on mAbs for prevention and treatment of COVID-19 have been issued by the WHO and US FDA, and efforts to prepare a regulatory environment supportive of drug development for future emerging and re-emerging infectious diseases have accelerated. The EMA published a concept paper on development of guidelines for non-clinical and clinical evaluation of mAbs for COVID-19. These trends indicate that the international regulatory landscape for mAbs against infectious diseases is entering a new era. We here provide an overview of the guidance documents issued by regulatory agencies, based on insights obtained from anti-SARS-CoV-2 mAbs during the COVID-19 pandemic. We also discuss the challenges and future prospects for the development of mAbs against infectious diseases, particularly in situations requiring rapid responses during pandemics.