Sanofi is advancing its respiratory vaccine pipeline by acquiring London-based Vicebio for $1.15 billion upfront, with additional payments possible based on clinical milestones. Vicebio's lead candidate, VXB-241, currently in Phase 1 trials, targets both respiratory syncytial virus (RSV) and human metapneumovirus (hMPV). This acquisition marks Sanofi's third deal in 2025 aiming to expand its vaccine portfolio beyond mRNA approaches. Early clinical data showed initial safety and tolerability, which helped accelerate Sanofi's purchase decision.