第1372期:A Chilean Tree Gives Hope for New Vaccines

Quillay trees are rare evergreens found mainly in the South American country of Chile. And they are increasingly important to producing new vaccines.

奎莱树是罕见的常青树，主要分布在南美国家智利。它们对于生产新疫苗越来越重要。

The native Mapuche people have long used them to make soap and medicine. In recent years, quillay trees, also known as quillaja saponaria, have been used in the processing of food and drinks. They have also been used to make a highly successful vaccine against shingles, a painful viral disease, and the world’s first malaria vaccine.

土著马普切人长期以来一直用它们制作肥皂和药品。近年来，奎莱树也被称为皂荚树，已被用于食品和饮料的加工。它们还被用来制造非常成功的带状疱疹疫苗，一种痛苦的病毒性疾病，以及世界上第一种疟疾疫苗。

Now, molecules extracted from the bark, or outer covering, of older quillay trees are being used for a COVID-19 vaccine. It is being developed by American drug-maker Novavax. Over the next two years, Novavax plans to produce billions of treatments of the vaccine for use in developing countries.

现在，从较老的奎莱树的树皮或外壳中提取的分子被用于 COVID-19 疫苗。它由美国制药商 Novavax 开发。在接下来的两年中，Novavax 计划生产数十亿种疫苗用于发展中国家。

Novavax uses two molecules to make adjuvant, a substance that improves the human immune system. One of those, called QS-21, is more difficult to find. The substance is found mainly in quillay trees that are at least 10 years old.

Novavax 使用两个分子来制造佐剂，这种物质可以改善人体免疫系统。其中一种称为 QS-21，更难找到。该物质主要存在于至少 10 年树龄的奎莱树中。

British drug-maker GlaxoSmithKline uses QS-21 in its highly successful vaccine against shingles called Shingrix. It is also used in several other promising experimental vaccines. The quillay-based adjuvant used in Shingrix is also part of the world’s first malaria vaccine, Mosquirix.

英国制药商葛兰素史克 (GlaxoSmithKline) 在其名为 Shingrix 的带状疱疹疫苗中使用了 QS-21。它还用于其他几种有希望的实验疫苗。Shingrix 中使用的基于奎莱的佐剂也是世界上第一种疟疾疫苗 Mosquirix 的一部分。

Less than one milligram of quillay extract is required to make a vaccine treatment. But the supply of quillay is stretched by the demand from other industries. Quillay products are used as a natural additive in animal feed. They also are used to kill harmful insects and as an agent to reduce pollution in mining.

进行疫苗治疗只需要不到 1 毫克的奎莱提取物。但奎莱的供应因其他行业的需求而捉襟见肘。Quilay 产品用作动物饲料中的天然添加剂。它们还用于杀死有害昆虫和作为减少采矿污染的药剂。

Some drug-makers are developing a manufactured version of QS-21. But it could take years to get approval. Exchanging the substance for another in any existing vaccine would require new drug tests to prove the product is safe and effective.

一些制药商正在开发 QS-21 的制造版本。但获得批准可能需要数年时间。在任何现有疫苗中将这种物质换成另一种物质都需要进行新的药物测试以证明该产品是安全有效的。

Jason Paragas, a vice president at drug company Agenus, said, “The shortage of QS-21 has been an issue for a while.” He added, “We saw it before COVID, and we made the hard decision that we had to change.”

制药公司 Agenus 的副总裁 Jason Paragas 说：“QS-21 的短缺问题已经有一段时间了。”他补充说：“我们在 COVID 之前就看到了，我们做出了必须改变的艰难决定。”

The American company in Massachusetts stopped selling the natural version of QS-21 several years ago. It now centers on trying to grow it from quillay plant cells in a laboratory. Paragas said it is too soon to know when it will be ready.

几年前，这家位于马萨诸塞州的美国公司停止销售 QS-21 的天然版本。现在的重点是尝试在实验室中从奎莱植物细胞中培育出它。帕拉加斯说，现在知道什么时候准备好还为时过早。

Botanical Solution, a California-based company, says it can already produce QS-21 from quillay seeds in the laboratory. The company adds that it aims to produce the substance in large quantities for drug companies.

总部位于加利福尼亚的公司 Botanical Solution 表示，它已经可以在实验室中从奎莱种子中生产 QS-21。该公司补充说，它的目标是为制药公司大量生产这种物质。

No one knows how many healthy quillay trees are left in Chile to meet the demand. Experts and industry officials believe that they will at some point need to switch to grow the evergreens on farms or in laboratories.

没有人知道智利还剩下多少健康的奎莱树来满足需求。专家和行业官员认为，他们在某个时候需要转向在农场或实验室种植常青树。

Ricardo San Martin developed the pruning and extraction process that created the modern quillay industry. He said producers must immediately work toward making quillay products from younger, farm-grown trees.

Ricardo San Martin 开发的修剪和提取工艺创造了现代奎莱产业。他说，生产商必须立即努力从更年轻的农场种植的树木中生产奎莱产品。

“My estimate four years ago was that we were heading towards the sustainability limit,” he said.

“我四年前的估计是，我们正朝着可持续性极限迈进，”他说。

Quillay producers say the harvest can continue for now without destroying the supply of older trees. Novavax told Reuters that the company is working with suppliers to make sure “life-saving vaccines will be prioritized.”

奎莱生产商表示，现在可以继续收割，而不会破坏老树的供应。Novavax 告诉路透社，该公司正在与供应商合作，以确保“优先使用挽救生命的疫苗”。

Andres Gonzalez runs Desert King International which operates a quillay farm in Chile. It is Novavax’s only supplier and the largest quillay exporter in the country. He said it produces enough quillay extract from older trees to make up to 4.4 billion vaccine treatments in 2022.

安德烈斯·冈萨雷斯 (Andres Gonzalez) 经营着沙漠之王国际公司，该公司在智利经营着一家奎莱农场。它是 Novavax 唯一的供应商，也是该国最大的奎莱出口商。他说，它从老树中生产的奎莱提取物足够到 2022 年进行 44 亿次疫苗治疗。

With new supplies from privately owned forests, he said, the operation can meet demand for the rest of this year and part of the next. He admitted, however, that “at some point, these native forests will come to an end.”

他说，有了来自私有森林的新供应，这项业务可以满足今年剩余时间和明年部分时间的需求。然而，他承认，“在某个时候，这些原生森林将走到尽头。”

Gustavo Cruz is a researcher at the University of Chile who worked with San Martin to industrialize the production of quillay. He said he generally trusts quillay producers to deal with supply and demand. He is more worried about other threats – especially a lack of water and fire.

Gustavo Cruz 是智利大学的研究员，他与圣马丁合作将奎莱的生产工业化。他说，他通常信任奎莱生产商来处理供需问题。他更担心其他威胁——尤其是缺水缺火。

“The trees do eventually regrow,” he said, “but there comes a time when they don't anymore.”

“树木最终会重新生长，”他说，“但有时它们会不再生长。”