Sanofi explores the acquisition of Vicebio and its Molecular Clamp technology, highlighting how it strengthens the company’s respiratory vaccine portfolio with next-generation combination candidates.

Q: Sanofi has described the acquisition of Vicebio as a step toward next-generation combination vaccines. What gaps or opportunities does this address in your existing respiratory vaccine portfolio? 

A: The acquisition of Vicebio enhances Sanofi’s respiratory vaccine portfolio by introducing a non-mRNA combination vaccine candidate targeting RSV and hMPV, complementing our existing flu and RSV prevention offerings. Also, Vicebio’s innovative Molecular Clamp technology enables us to develop fully liquid combination vaccines that could provide protection against multiple respiratory viruses with a single immunisation, addressing the unmet medical need for comprehensive protection against co-circulating respiratory pathogens in vulnerable populations such as older adults. This strategic addition allows us to offer healthcare providers and patients greater choice in prevention strategies while expanding our technological capabilities in developing next-generation vaccines that can effectively target multiple respiratory threats simultaneously.

Q: The Molecular Clamp technology is a key asset in this acquisition. Could you elaborate on how this platform compares to other stabilisation approaches in vaccine design, particularly in terms of speed, stability, and immunogenicity? 

A: The Molecular Clamp technology represents a significant advancement in vaccine design by stabilising viral proteins in their native shape, which enhances immune system recognition and potentially leads to stronger, more targeted immune responses. Unlike some other stabilisation approaches that may alter protein structure, this technology preserves the authentic antigenic properties of viral proteins, potentially improving vaccine efficacy. From a development perspective, the platform enables quicker development of fully liquid combination vaccines without requiring complex freeze-drying processes. A key advantage is the thermostability of resulting vaccines, which can be stored at standard refrigeration temperatures between 2-8°C, eliminating specialised cold chain requirements that complicate distribution. This purposefully simple yet thoughtful approach to vaccine design offers practical benefits for manufacturing, distribution, and administration while maintaining the immunological integrity needed for effective protection.

Q: With VXB-241 targeting both RSV and hMPV and VXB-251 adding PIV3, what are the challenges of developing bivalent or trivalent vaccines for co-circulating respiratory viruses in older adults? 

A: Developing effective bivalent or trivalent vaccines for co-circulating respiratory viruses in older adults presents several complex challenges. Despite causing similar clinical symptoms, RSV, hMPV, and PIV3 are antigenically distinct viruses, requiring the vaccine to generate specific and adequate immune responses against each pathogen without interference between components. The immunosenescence characteristic of older adults further complicates vaccine development, as their immune systems typically mount less robust responses to vaccination, potentially necessitating special formulations or adjuvants to achieve protective immunity. Additionally, ensuring balanced efficacy across all viral targets while maintaining an acceptable safety profile is particularly important in this vulnerable population, where these viruses can lead to serious complications including hospitalisation and mortality. Our approach with Vicebio’s vaccine candidates aims to address these challenges by leveraging the Molecular Clamp technology to present viral antigens in their most immunogenic form. 

Q: Sanofi is already active in mRNA-based vaccines. How does adding a non-mRNA approach with Vicebio’s technology help diversify your R&D pipeline and manage future vaccine development risk? 

A: Adding Vicebio’s non-mRNA technology to our portfolio creates a more balanced and resilient R&D pipeline that can better address diverse healthcare needs and mitigate development risks. While we remain committed to advancing our mRNA platform, incorporating complementary technologies allows us to match the most appropriate approach to specific disease targets and patient populations. The Molecular Clamp technology offers distinct advantages in terms of thermostability and manufacturing simplicity that complement our existing capabilities, enabling us to develop vaccines with different benefit profiles. This technological diversification strengthens our position in the competitive vaccine landscape and provides multiple pathways to address emerging health challenges. By maintaining expertise across different vaccine platforms, we can more effectively respond to evolving scientific insights and public health needs while reducing our vulnerability to platform-specific limitations or setbacks. 

Q: How important is the ability to store vaccines at standard refrigeration temperatures, and what role does this play in global access and distribution strategies? 

A: The ability to store vaccines at standard refrigeration temperatures (2-8°C) is a critical factor in achieving equitable global vaccine access and represents a significant advantage of the Molecular Clamp technology. Standard refrigeration eliminates the complex ultra-cold chain infrastructure required for some mRNA vaccines, substantially reducing logistical barriers and costs associated with vaccine distribution. This thermostability enables integration into existing healthcare infrastructure worldwide. Furthermore, standard refrigeration temperatures extend shelf life under practical storage conditions, reducing wastage and improving cost-effectiveness of vaccination programs. The additional benefit of offering these vaccines in prefilled syringes enhances safety, simplifies administration, and improves operational efficiency across diverse healthcare settings. 

Q: Looking ahead, how might Sanofi integrate Vicebio’s platform to accelerate innovation beyond respiratory vaccines? Could this be a stepping stone toward broader combination vaccines, or even pandemic preparedness? 

A: The Molecular Clamp has been designed primarily to support vaccine development. Given that this approach allows for better stabilisation of proteins in the right confirmation, and because it includes features to reduce the immune response mounted against the clamp (immunosilenced), we will evaluate post-closing the potential of this technology in non-vaccine applications