Sanofi announced a $1.15 billion upfront acquisition of Vicebio, a London-based biotech developing combination vaccines targeting respiratory syncytial virus (RSV) and human metapneumovirus (hMPV). The deal, expected to close in Q4 2025, includes potential milestone payments up to $450 million and adds a novel ‘molecular clamp’ vaccine technology to Sanofi’s portfolio, complementing its existing influenza and RSV vaccines. Vicebio's lead candidate, VXB-241, is in Phase I trials with favorable safety data in older adults. This acquisition underscores Sanofi’s strategic diversification beyond mRNA vaccine platforms in respiratory diseases.