Fridge-free vaccine shows promise for reaching millions more people worldwide

The world-first trial of a fridge-free tetanus-diphtheria vaccine at University Hospital Southampton (UHS) has produced encouraging results that could improve access worldwide to crucial treatments.

Around half of vaccines are wasted globally each year, according to the World Health Organization. Millions of vaccine doses are lost because of temperature changes during storage and transport.

Fridge-free vaccines have the potential to transform vaccine delivery by reducing this dependence on refrigeration. This would improve access in more isolated communities and cut the environmental impact by reducing vast amounts of energy that lead to emissions.

The phase I study found the vaccine was well tolerated, with no vaccine-related serious adverse events. Results have been published today in The Lancet group’s eClinicalMedicine.

The reformulated vaccine, known as SPVX02, was developed by UK-based biotech company Stablepharma using its StablevaX technology.

The trial took place in the National Institute for Health and Care Research (NIHR) Clinical Research Facility at UHS and was delivered through the NIHR Biomedical Research Centre: Southampton.

Professor Saul Faust, UHS consultant paediatrician and director of the NIHR Clinical Research Facility, who led the study, said:

“Keeping vaccines cold from the factory to the patient is one of the biggest challenges facing immunisation programmes worldwide. Our study suggests that this vaccine can remain safe and effective without refrigeration.

“If larger studies confirm these findings, this technology could help transform the way vaccines are stored and delivered around the world.”

The research shows that SPVX02 can be stored at temperatures of up to 30°C for at least two years without losing its effectiveness. Scientists are now investigating whether it can remain stable for as long as four years.

Researchers have also demonstrated that the vaccine remains stable, and fully potent, after three cycles of extreme temperature fluctuation from -20°C to +40°C.

The randomised trial, which also involved the Medicines Evaluation Unit (MEU) in Manchester, enrolled 60 healthy adults.

By 28 days after vaccination, all participants receiving SPVX02 achieved protective antibody levels against both tetanus and diphtheria, demonstrating immune responses comparable to licensed vaccines.

The eClinicalMedicine publication follows the launch of a Phase 2b trial that will further assess the vaccine in a larger group of participants.

Stablepharma's technology platform, StablevaX, can be applied to vaccines, small molecules, peptides and biologics. They are currently working with a partner to thermostabilise small molecule oncology and anti-infective products, in addition to other vaccines.

Özgür Tuncer, Stablepharma CEO and Executive Director, said:

“This peer reviewed validation represents a pivotal moment for our StablevaX platform and the future of thermostable vaccines. These findings strengthen the scientific and global health case for a new generation of fridge free vaccines, particularly in regions where cold chain limitations hinder equitable access.”

Dr Bruce Roser MB BS, PhD, Stablepharma founder and board member said:

“Reliable and safe fridge-free vaccines could be a game changer for global health - helping life-saving vaccines reach millions more people, wherever they live, and making immunisation programmes more sustainable, reliable and equitable for future generations.”

Health and Social Care Minister Diana Johnson said:

“This pioneering research demonstrates how British innovation is helping to tackle some of the biggest challenges in global healthcare, and providing life-saving breakthroughs for use around the world.

“Right now, people are dying of preventable diseases all over the world, not due to a lack of vaccines, but a lack of refrigeration. Fridge-free vaccines have the potential to be a game-changer for global health, especially for people in remote communities, or regions affected by conflict.

"Backed by NIHR's world-leading research, this breakthrough shows once again how our investment in science and life sciences is driving better health outcomes, while supporting economic growth and reinforcing the UK's position at the forefront of medical innovation."

Chief Scientific Adviser at the Department of Health and Social Care (DHSC) and Chief Executive Officer of the NIHR, Professor Lucy Chappell, said:

"Vaccines save lives, but only if they can reach the people who need them. Removing the need for refrigeration could be transformative for communities around the world.

"This is a great example of UK research once again leading the way to bring life-saving treatments to people where they are, making health equity a reality."

NIHR-funded research infrastructure enabled Stablepharma to conduct this first-in-human trial and generate the clinical evidence needed to advance this UK-developed technology.

This shows how the UK’s research system works with innovative companies to translate promising science into globally relevant products, opening up new markets and making vaccines easier to store, transport and deliver around the world.

Stablepharma’s SPVX02 vaccine has been developed with support from Innovate UK, part of UK Research and Innovation (UKRI). It is a reformulated version of the WHO-prequalified Tetadif tetanus-diphtheria vaccine. Scientists from the UK Health Security Agency (UKHSA) provided specialist laboratory testing.

Stablepharma expects to complete the clinical development programme for SPVX02 by 2027.