Desert plants inspired a vaccine that survives without refrigeration

A powder-based vaccine inspired by desert plants stayed stable for a full year at room temperature, according to trial results from the UK's National Institute for Health and Care Research. The idea comes from resurrection plants, which can sit lifeless for months in African and South American drought, then revive when it rains. Their trick is a sugar called trehalose that protects their cells while they wait. Researchers used the same sugar to turn a liquid tetanus-diphtheria vaccine into a powder that revives with a splash of water. In tests it survived temperature swings from minus 4°F to 104°F, roughly the journey from an aircraft cargo bay to a truck on a rural road. Given to 60 people, it was safe and produced immune responses comparable to refrigerated versions. "This obviously has potential to remove cold chain dependence, reduce wastage and improve access," said Professor Saul Faust of the NIHR facility in Southampton. A 160-person trial starts in the coming months.