Optimally fixed F protein on the surface of RSV-infected cells for RSV binding and neutralizing assays.

Respiratory syncytial virus (RSV) presents a significant global public health challenge, contributing substantially to the disease burden worldwide. As numerous F protein-based vaccine candidates advance into clinical trials, robust evaluation methods are essential. Here, we developed a cell-based ELISA platform to rapidly evaluate serum antibody responses to these vaccines. By treating RSV-infected cells with 4% formaldehyde or 60% methanol, the cell-surface F proteins were stabilized in the pre-fusion (pre-F) or post-fusion (post-F) conformations, respectively. This platform efficiently determines the binding and neutralizing activities of post-immunization serum antibodies, providing an effective method for evaluating the efficacy of RSV vaccine candidates.