Antibodies to combat melioidosis: bridging immune mechanisms with diagnostics and therapeutic potential

PURPOSE OF REVIEW: Melioidosis, caused by the Gram-negative soil bacterium Burkholderia pseudomallei , is a frequently fatal (sub)tropical infection with a substantial global burden. This review summarizes current insights into antibody-mediated immunity in melioidosis and its clinical potential. RECENT FINDINGS: Antibodies against B. pseudomallei polysaccharides and protein antigens promote bacterial clearance through opsonophagocytosis and complement activation, reducing intracellular spread. People who survive melioidosis develop broader and more durable antibody repertoires than nonsurvivors. Protective antibody responses vary by antigen class and are influenced by host factors, notably diabetes, a main risk factor for melioidosis. Diagnostic serology has advanced from low-performing indirect hemagglutination to single-antigen tests and multiplex platforms. Performance, however, is specimen-dependent, limited by cross-reactivity with related Burkholderia spp., and by cost and resource constraints in endemic settings. In preclinical models of melioidosis, monoclonal antibodies against B. pseudomallei confer passive protection and are being developed for prophylaxis, adjunctive therapy, and as platforms for antibody-antibiotic conjugates or vaccine design. SUMMARY: Antibody responses to key virulence factors correlate with disease course and are increasingly studied for diagnostic and therapeutic applications. This review aids in informing novel diagnostics and guide antibody-based therapies offering new directions for clinical management and prevention of this high-burden but underrecognized infection.