Down a dusty farm track in Chilean wine country, behind a wooden gate wrapped in chains, forestry experts are nursing a plantation of saplings whose bark holds the promise of potent vaccines.

Quillay trees, technically known as Quillaja saponaria, are rare evergreens native to Chile that have long been used by the indigenous Mapuche people to make soap and medicine. In recent years, they have also been used to make a highly successful vaccine against shingles and the world’s first malaria vaccine, as well as foaming agents for products in the food, beverage and mining industries.

Now two saponin molecules, made from the bark of branches pruned from older trees in Chile’s forests, are being used for a Covid-19 vaccine developed by drugmaker Novavax.

Read the full Reuters story here.