DT-preF

**DT-preF** is an engineered subunit vaccine immunogen consisting of the respiratory syncytial virus (RSV) fusion (F) protein stabilized in its prefusion conformation through two targeted dityrosine crosslinks. This structure-based design locks key prefusion-specific epitopes (Site Ø and Site IV/V interface), enhancing thermostability, shelf-life, and immunogenicity compared to prior stabilizers like DS-Cav1. Developed by Calder Biosciences, it elicits 11-fold higher neutralizing antibody titers in mice, overcomes immunosenescence in aged models with high-dose alum formulation, and provides sterile protection in cotton rats against RSV challenge, positioning it as a next-generation RSV vaccine candidate.