J Infect Dis. 2025 Jul 18:jiaf375.
Abstract
Background: Respiratory syncytial virus (RSV) F protein contains major neutralizing epitopes, including sites Ⅱ, Ⅲ, Ⅳ, Ⅴ, and Ø, which are the targets of newly developed vaccines and monoclonal antibodies. However, data on serum epitope-specific antibodies (ESAs) and their association with neutralizing activity (NA) are limited. Hence, in the current study, we aimed to evaluate ESA levels in healthy Japanese adults and their association with NA levels against various clinical isolates.
Methods: Serum samples were collected from pediatricians from February to March 2020. Levels of each ESA and NA against RSV clinical isolates were quantified using enzyme-linked immunosorbent assays and neutralizing assays. Pearson's correlation analysis was used to estimate the association between ESA and NA levels.
Results: Ninety-two healthy adults aged 28-75 years (median, 41.5 years; 63.0% male) were included. The ESA levels (median [interquartile range]) differed significantly at sites II, III, IV, V, and Ø (paired t-test, p<0.001 for all combinations). ESA levels were lower at sites Ⅳ and Ø (2.7 [2.2-3.4] and 10.2 [8.1-13.5] μg/mL, respectively) than at other sites (41.9 [35.0-56.7] at II, 16.6 [9.4-44.1] at III, and 35.3 [28.4-42.4] at V). Associations between ESA and NA levels differed based on the subtype and mutations.
Conclusions: Serum ESA and NA levels should be considered in the development and application of vaccines and monoclonal antibody therapies. Monitoring serum ESA levels in the general population and dominant RSV F protein genes is essential for treatment selection.
Products: RVV02814, DVV02807, Anti-HRSV-A F/Fusion glycoprotein F0 Antibody (MPE8), Research Grade Suptavumab
