Is Chilean tree bark a key ingredient?

The quillaja tree, which grows in the Chilean Andes, has traditionally been used by the Mapuche to treat colds and inflammation. But it could play a significant role in a vaccine for the novel coronavirus. The Chilean biotech company Desert King is a significant actor in the race to develop a COVID-19 vaccine. The firm has developed a procedure that allows for active agents to be extracted from the bark and wood of the quillaja tree, which only grows in Chile. Desert King sells the resulting powder to a British subsidiary of the US vaccine development company Novovax.

Novovax announced in late September that it had initiated its first Phase 3 study to evaluate the efficacy and safety of its vaccine in the UK, and that it aimed to enroll 10,000 volunteers between the ages of 18 and 84 to take part. Currently, there are 11 COVID-19 vaccine candidates in the third phase of testing.

Desert King General Manager Andres Gonzales told DW that if all went well, production of the vaccine could start early next year.

Read more: Coronavirus vaccination: What are we actually waiting for?

Multipurpose foaming agents "A vaccine is comprised of two elements, an antigen and an adjuvant," explained Gonzalez. "The antigen activates a body's own defense, while the adjuvant helps release the antigen into the cells and also stimulates the body's immune response."

The quillaja tree, also known as the soap bark tree, has a high content of saponins, which are natural emulsifiers and multipurpose foaming agents. They can be used to bind substances that usually do not mix, such as water and oil, but they can also serve as adjuvants.

The quillaja tree, which grows in the Chilean Andes, has traditionally been used by the Mapuche to treat colds and inflammation. But it could play a significant role in a vaccine for the novel coronavirus. The Chilean biotech company Desert King is a significant actor in the race to develop a COVID-19 vaccine. The firm has developed a procedure that allows for active agents to be extracted from the bark and wood of the quillaja tree, which only grows in Chile. Desert King sells the resulting powder to a British subsidiary of the US vaccine development company Novovax.

Novovax announced in late September that it had initiated its first Phase 3 study to evaluate the efficacy and safety of its vaccine in the UK, and that it aimed to enroll 10,000 volunteers between the ages of 18 and 84 to take part. Currently, there are 11 COVID-19 vaccine candidates in the third phase of testing.

Desert King General Manager Andres Gonzales told DW that if all went well, production of the vaccine could start early next year.

Multipurpose foaming agents

"A vaccine is comprised of two elements, an antigen and an adjuvant," explained Gonzalez. "The antigen activates a body's own defense, while the adjuvant helps release the antigen into the cells and also stimulates the body's immune response."

The quillaja tree, also known as the soap bark tree, has a high content of saponins, which are natural emulsifiers and multipurpose foaming agents. They can be used to bind substances that usually do not mix, such as water and oil, but they can also serve as adjuvants. After conducting studies into the 50 odd saponins contained in the quillaja tree, Desert King identified two substances — QS7 and QS21 — that could function as an adjuvant in a potential vaccine.

"We are already producing industrial quantities of quillaja for Novavax," said Gonzalez.

The quillaja tree can grow up to 20 meters (65 feet) high; its trunk can reach a diameter of 1.5 meters. It flowers from October to January, producing an aromatic honey. The evergreen, with smooth and leathery leaves, has small, yellowish-white star-formed blossoms. With its five follicles, the woody fruit of the tree resembles star anise.

Ref: dw.com