Vaccines are notoriously difficult to transport to remote or dangerous places, as they spoil when not refrigerated. Formulations are safe between 2°C and 8°C, but at other temperatures the proteins start to unravel, making the vaccines ineffective. As a result, millions of children around the world miss out on life-saving inoculations.
However, scientists have now found a way to prevent warmed-up vaccines from degrading. By encasing protein molecules in a silica shell, the structure remains intact even when heated to 100°C, or stored at room temperature for up to three years.
The technique for tailor-fitting a vaccine with a silica coat – known as ensilication – was developed by a Bath team in collaboration with the University of Newcastle. This pioneering technology was seen to work in the lab two years ago, and now it has demonstrated its effectiveness in the real world too.
In their latest study, published in the journal Scientific Reports, the researchers sent both ensilicated and regular samples of the tetanus vaccine from Bath to Newcastle by ordinary post (a journey time of over 300 miles, which by post takes a day or two). When doses of the ensilicated vaccine were subsequently injected into mice, an immune response was triggered, showing the vaccine to be active. No immune response was detected in mice injected with unprotected doses of the vaccine, indicating the medicine had been damaged in transit.
Read more at University of Bath
Image: The enscilliation project has been led by Asel Sartbaeva from the University of Bath. (Credit: University of Bath)