A study published today in Scientific Reports found that ensilication can improve the thermal stability of proteins in vaccines. Most vaccines require refrigeration during transport and storage in order to prevent thermal denaturation and loss of potency. Supporting this cold chain can be expensive and also problematic in developing countries.
Ensilication, a method developed at the University of Bath, "shrink-wraps" vaccine proteins in position using layers of silica that build up into a cage around the molecules—so they don't unravel when exposed to temperatures that would usually break them down. The proteins are held in place until ready to be removed from the silica cage and delivered.
The University of Bath team, which is working on a new tuberculosis vaccine, demonstrated that the TB antigen ag85b and a vaccine fused with the adjuvant protein Sbi are sensitive to breaking down outside of refrigerated temperatures. They then showed that these vaccine components were protected from heat damage when ensilicated and kept on a shelf at room temperature for long periods of time without loss of structure and function.
With up to 50% of vaccines being thrown away, and refrigeration raising vaccine costs by up to 80%, this is a major global health challenge that we need to overcome. “By demonstrating for the first time that ensilication works to protect vaccine-relevant proteins from breaking down outside a fridge we're a big step closer to achieving this goal," explained the inventor of ensilication Dr Asel Sartbaeva.