Soapbark branches out to fill essential role in vaccine recipes
The soapbark tree has long been used in traditional medicines, but is now coveted for some of our newest vaccines
When it rains in the forests of central Chile, soapy suds can be seen forming on exposed sections of Quillaja saponaria, the soapbark tree – an evergreen that grows abundantly there. Chileans refer to it as the ‘quillay’ tree, meaning ‘to wash’, because its bark is rich in natural surfactants called saponins. Traditionally, those saponins are used industrially as foaming agents and emulsifiers in the food and beverages industry. But since 2017, the soapbark tree has had a new role: supplying adjuvants – vaccines’ hidden helpers.