Antibody engineering for SFTS treatment: frontier progress and translational challenges.

Severe Fever with Thrombocytopenia Syndrome (SFTS), a highly fatal tick-borne infectious disease caused by SFTS virus (SFTSV), currently lacks globally approved specific antiviral drugs or vaccines, although favipiravir was approved in Japan for SFTS treatment in June 2024 based on data from non-randomized, uncontrolled single-arm trials. Antibody engineering has emerged as a core strategy against SFTSV, leveraging its advantages of high specificity, potent neutralizing activity, and engineerability. This review systematically examines the mechanisms of action and preclinical progress of monoclonal antibodies, nanobodies, and bispecific antibodies (bsAbs) for SFTS treatment. It analyzes translational challenges-including immunogenicity, manufacturing processes, cost control, drug resistance, and clinical trial design-and proposes a strategic prioritization matrix and future research directions such as multispecific antibody development, artificial intelligence (AI)-assisted design, combination therapy strategies, and international multicenter collaboration. This review aims to provide a systematic reference for the clinical translation of SFTS antibody therapeutics.