Developing Thermostable Vaccines To Improve Accessibility Worldwide
The challenges related to keeping vaccines adequately cold in many parts of the world has highlighted the need to develop vaccines that are thermostable. In doing so, it would be possible to relieve key bottlenecks in the storage and supply of vaccines, enabling more patients access to the life-saving vaccines they require. Stablepharma has patented a novel technology to improve healthcare for those most at risk of death and disability caused by vaccine-preventable diseases.
We spoke to Ozgur Tuncer, chief executive officer of Stablepharma to find out more about the company’s thermo-stabilization technology called StablevaX™ and how it is being used as a complementary technology for COVID-19 vaccines. He also highlights the impact “fridge-free” vaccines could have more generally.
Laura Lansdowne (LL): Could you comment on the importance of, and challenges related to, equitable and efficient vaccine delivery?
Ozgur Tuncer (OT): Immunization saves millions of lives every year and is widely recognized as one of the world’s most successful health interventions. Vaccines save lives but yet, there are still approximately 20 million children in the world today who are not receiving the vaccines they need. Many miss out on vital vaccines during adolescence, adulthood and into old age. According to the Gates Foundation, every 20 seconds a child dies from disease that could be prevented by vaccination. Distribution, storage and particularly the “cold chain” continue to be major barriers in terms of accessibility, especially in certain parts of the world with poor/inadequate infrastructures. Furthermore, 50% of vaccines are wasted globally according to the World Health Organization despite $400 M spent annually on the global “cold chain”. If we can solve the problem, we can alleviate significant suffering and save many lives.
LL: Most existing liquid vaccines require refrigerated storage. What would happen if a vaccine that typically requires refrigeration, was accidentally submitted to temperatures outside of the target range?
OT: Vaccines are thermally unstable products that lose their effectiveness if exposed to temperatures which are either too hot or too cold – and most require constant refrigeration between 2–8 °C. All of the current COVID-19 vaccines require cold chain conditions from the factory to the patient to maintain potency, with the two mRNA vaccines (Pfizer/BioNTech and Moderna) requiring -20 °C to -80 °C storage. Cold chain requirements are one of the key reasons for the 50% wastage of vaccines globally.
Kate Robinson (KR): What factors have fuelled efforts into eliminating the need for the refrigeration of vaccines?
OT: Unquestionably, the COVID-19 pandemic has fuelled efforts into eliminating the need for the refrigeration of vaccines. Wide media coverage on how COVID mRNA vaccines cannot reach all corners of the world due to storage requirements of -20 °C to -80 °C has been instrumental. It was a tipping point where the world concluded that we must work on eliminating the need for refrigeration in order to be able to provide better access to vaccines. As our Chairman Dr. Bruce Roser said: “We are not safe until we are all safe”.
LL: Can you highlight some of the encouraging in vitro data that has emerged from your COVID mRNA program?
OT: We have embarked on a stepwise approach in order to develop a fridge-free COVID mRNA vaccine. Stablepharma started the thermo-stabilization programme of the naked COVID mRNA in February 2021, following the launch of other COVID mRNA vaccines. StablevaX™ prototypes of SARS-CoV-2 RNA stabilized by vacuum or freeze drying and stored at 25 °C or 45 °C for one and two months have been quantitatively assessed by the University Hospital La Paz in Madrid, Spain. RT-qPCR analysis of SAR-CoV-2’s S-gene (Spike) and E-gene (Envelope) indicates RNA integrity is fully maintained at high ambient temperatures. This important result triggered our decision to allocate resources to the stabilization of the entire COVID mRNA/Lipid nanoparticle (LNP) complex vaccine.
LL: Can you tell us more about your thermo-stabilization technology, StablevaX™, how does it work?
OT: StablevaX™ offers a novel approach to vaccine stabilization that enables otherwise highly sensitive vaccines to be stored at room temperature. Stablepharma does not make or develop new vaccines – we take existing vaccines and stabilize them, with our reformulation stored either in a porous matrix or in an immediately dissolvable form. This is then housed in the barrel of a syringe, which acts as manufacturing, storage and delivery vessel. By housing the pre-dosed and stable vaccine in a syringe, we ensure safe, efficient and waste-free delivery without the need for a “cold chain”.
KR: Could this technology be applied to vaccine types beyond those based on mRNA?
OT: Yes absolutely. In fact, we think the StablevaX™ technology could be applicable to more than 60 different vaccines. Our lead vaccine programme is Tetanus diphtheria (Td) where we are working with the European vaccine manufacturer Bul Bio. We have shown in animal potency challenge trials that the Td-StablevaX™ vaccine has the same potency as the original Tetadif vaccine, even when it is stored at highly elevated temperatures of 45 °C for 2 months. The initial data is so encouraging that we are now moving forward with the first-in-human clinical trials to launch the world’s first fridge-free vaccine!
Ozgur Tuncer was speaking with Laura Lansdowne, Managing Editor and Kate Robinson, Editorial Assistant for Technology Networks.