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 (Quillaja saponaria) are rare evergreens native to Chile that have long been used by the indigenous Mapuche people to make soap and medicine. Recently, they have also been used to make a 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 Inc. The chemicals are used to make adjuvant, a substance that boosts the immune system.
Over the next two years, Novavax, which is based in Maryland, US, plans to produce billions of doses of the vaccine, mostly for low and middle-income countries, which would make it one of the largest Covid-19 vaccine suppliers in the world.
With no reliable data on how many healthy quillay trees are left in Chile, experts and industry officials are divided on how quickly the supply of older trees will be depleted by rising demand. But most agree that industries relying on quillay extracts will at some point need to switch to plantation-grown trees or a lab-grown alternative.
A Reuters analysis of export data from trade data provider ImportGenius shows the supply of older trees is under increasing pressure. Exports of quillay products more than tripled to more than 3,600 tonnes a year in the decade before the pandemic.
Quillay producers and their customers say the harvest can continue for now without decimating supply of older trees.
“We continue to monitor the situation in Chile, but at this time we are confident in our supply,” Novavax said in a statement. The company also said uses such as “life-saving vaccines” will be prioritised.
The desert-plant extract company Desert King International, which runs the Casablanca plantation, is Novavax’s sole supplier of quillay extracts. Its manager in Chile, Andres Gonzalez, said it is set to produce enough quillay extract from older trees to make up to 4.4 billion vaccine doses next year.