Live Vaccines Protected by a Sugar Glass Film Do Not Require Refrigeration

Researchers have announced the development of a process for preserving living, virus-based vaccines without the need for refrigeration, a major step in providing modern healthcare to countries in the developing world.

Live recombinant viral vectors based on adenoviruses and poxviruses are among the most promising platforms for development of new vaccines against diseases such as malaria, tuberculosis, and HIV-AIDS. Vaccines based on live viruses must remain infectious to be effective, so therefore need continuous refrigeration to maintain stability and viability, a requirement that can be costly and difficult, especially in developing countries.

Investigators from Nova Bio-Pharma Technologies (Leicester, UK) have developed a process for the thermostabilization of live viral vaccine vectors. By slowly drying vaccines suspended in solutions of disaccharide stabilizers such as sucrose and trehalose onto a filter-like support membrane at ambient temperature, an ultrathin glass was deposited onto the fibers of the inert matrix. The matrix with its stabilized vaccine was then incorporated into a sterile syringe for instant reconstitution and injection. Vaccines incorporated into this hypodermic rehydration injection system (HydRIS) were recently evaluated at Oxford University (UK).

Results published in the February 17, 2010, online edition of the journal Science Translational Medicine revealed that viral titer and immunogenicity of two recombinant vaccine vectors--E1/E3-deleted human adenovirus type 5 and modified vaccinia virus Ankara--immobilized on membranes, protected by a layer of sugar-glass could be completely recovered after storage at up to 45 ^oC for six months and even longer with minimal losses. Furthermore, the vaccines could be kept for a year and more at 37 ^oC with only miniscule losses in the amount of viral vaccine reobtained from the membranes.

"This new technique of drug delivery is one of the most exciting developments in the British pharmaceutical and biotechnology industries, especially as it can be used for highly unstable products, for instance vaccines for malaria,” said Dr. Peter White, managing director of Nova Bio-Pharma Technologies. "The benefits it offers to our customers--with many now looking for more efficient, cost-effective ways of delivering drugs--and the impact it can have abroad, cannot be overstated.”

Related Links:
Nova Bio-Pharma Technologies
Oxford University