Here in the dusty Casablanca region of Chilean wine country lies what could be the key natural resource behind a new COVID-19 vaccine for low- and middle-income countries: The bark of quillay trees.
Long used by the indigenous Mapuche people to make soap and medicine, the trees also been used to make a highly successful vaccine against shingles and the world’s first malaria vaccine.
Now, two 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 Maryland-based Novavax.
The chemicals are used to make a substance that boosts the immune system. Over the next two years, Novavax 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 nearly everyone agrees that industries relying on quillay extracts will at some point need to switch to plantation-grown trees or a lab-grown alternative.
“My estimate four years ago was that we were heading towards the sustainability limit.”
Ricardo San Martin, who developed the pruning and extraction process that created the modern quillay industry, said producers must immediately work toward making quillay products from younger, plantation-grown trees.
Quillay producers and their customers say the harvest can continue for now without decimating the supply of older trees.
Andres Gonzalez, the manager of Desert King International, Novavax’s sole supplier of quillay extracts, told Reuters it is set to produce enough quillay extract from older trees to make up to 4.4 billion vaccine doses in 2022.
“We feel the responsibility and we believe that we are up to it but today we are quite confident that we are capable of producing it.”
A relatively small volume of quillay extract is required to make vaccines - just under one milligram per dose - but the supply is stretched by the demand from other industries.
While some have expressed confidence in producers’ ability to manage supply and demand, there are concerns about other threats - like drought and fire.