HQ Team
July 22, 2025: Sanofi SA will acquire UK-based Vicebio Ltd. for $1.6 billion to gain access to vaccine candidates for respiratory viruses and expand its vaccine design and development.
The France-headquartered Sanofi will bag a respiratory syncytial virus (RSV) and a human metapneumovirus vaccine (hMPV) to complement its position in the segment, where it is present in flu and RSV prevention, according to a statement. Vicebio will receive potential milestone payments of up to $450 million based on development and regulatory achievements.
The acquisition allows Sanofi to offer increased physician and patient choice in RSV and hMPV by adding a non-mRNA vaccine to its pipeline. There are currently no vaccines for use against hMPV.
Vicebio’s acquisition also gives Sanofi the British company’s ‘Molecular Clamp’ technology that stabilises viral proteins in their native shape, enabling the immune system to recognise and respond to them more effectively.
Liquid vaccines
This approach enables quicker development of fully liquid combination vaccines that can be stored at standard refrigeration temperatures (2–8°C), eliminating the need for freezing or freeze-drying, thereby simplifying manufacturing and distribution.
Fully liquid vaccines can be made available in prefilled syringes, enhancing ease of use, safety, and operational efficiency across healthcare settings.
“Vicebio’s ‘Molecular Clamp’ technology introduces a purposefully simple but thoughtful approach to further improve vaccine designs at a time when respiratory viral infections continue to impact millions globally”, said Jean-François Toussaint, Global Head of Research and Development Vaccines at Sanofi.
“This acquisition furthers Sanofi’s dedication to vaccine innovation with the potential to develop next-generation combination vaccines that could protect older adults against multiple respiratory viruses with a single immunisation.”
Milestone payments
The transaction is expected to close in the last quarter of this year, and the acquisition will not have a significant impact on Sanofi’s financial guidance for 2025, according to the statement.
Vicebio’s pipeline includes VXB-241, a bivalent vaccine candidate targeting RSV and hMPV, currently in an early-phase study in older adults, and VXB-251, a preclinical trivalent vaccine candidate targeting RSV, hMPV and parainfluenza virus Type 3 (PIV3).
RSV, hMPV, and PIV3 are leading causes of lower respiratory tract infections such as pneumonia. These viruses often cause overlapping symptoms such as cough, fever, and respiratory distress.
They are frequently co-circulating and contributing to seasonal surges in respiratory illness that can lead to older adult frailty, hospitalisation and, in some cases, death.
Vicebio was founded with investment from Medicxi and acquired the rights to the Molecular Clamp technology through a license from UniQuest, the commercialisation arm of The University of Queensland, Australia.
