Researchers Return to Alzheimer's Vaccines

Researchers Return to Alzheimer's Vaccines

研究人员重新关注阿尔茨海默症疫苗

【原文听力】

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　　By Gregory Stachel

　　27 November 2023

　　Researchers are renewing efforts to find Alzheimer's disease treatments that remove harmful proteins from the brain. Such vaccines could possibly offer an easier and lower-cost choice for millions of people, several scientists and industry leaders say.

　　The brain-wasting disease causes thinking and memory problems.

　　The U.S. government website ClinicalTrials.gov shows that at least seven possible Alzheimer's vaccines are in human testing or have completed such trials. The experimental treatments are designed to use the body's natural defense system to destroy Alzheimer's-linked proteins in the brain. The proteins are beta amyloid and tau.

　　The renewed interest in Alzheimer's vaccines follows a promising first attempt more than 20 years ago. That vaccine work halted after six percent of study volunteers developed a life-threatening brain condition called meningoencephalitis.

　　Researchers then found a safer method using closely targeted synthetic antibodies in patients. These antibodies avoid extreme immune system reaction.

　　Health care companies Eisai and Biogen launched a new medication called Leqembi and health care company Eli Lilly launched Donanemab. American government drug experts are reviewing the treatments.

　　The reported success of the drugs has strengthened the theories that amyloid removal is critical to fighting Alzheimer's.

　　Scientists believe they now understand what went wrong with the first vaccine. They are testing shots they hope will cause an immune reaction without causing too much inflammation.

　　Dr. Reisa Sperling is an Alzheimer's researcher at Mass General Brigham in Boston. She said she believes vaccines will play an important part as researchers look to prevent Alzheimer's. She said, "I'm very keen that that's where we need to go."

　　Sperling is leading a trial in people with Alzheimer's proteins in their brains but showing no signs of related problems. She is considering vaccines for her next study in people who have Alzheimer's proteins in their blood, but not enough to show on imaging of the brain.

　　Alzheimer's vaccines are still in the early stages and will require large, years-long trials to show they work.

　　But a vaccine given two or four times a year could offer a lower-cost solution than Leqembi. Leqembi is given twice a month. That could expand available treatment among the estimated 39 million people around the world with Alzheimer's.

　　Dr. Walter Koroshetz is director of the part of U.S. National Institutes of Health that deals with disorders involving the brain. He said of the vaccines, "They could be worldwide, and not that expensive."

　　I'm Gregory Stachel.

　　Julie Steenhuysen reported this story for Reuters. Gregory Stachel adapted it for VOA Learning English.

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　　作者：Gregory Stachel

　　2023年11月27日

　　研究人员正在重新加大努力，寻找能够从大脑中清除有害蛋白质的阿尔茨海默症治疗方法。几位科学家和行业领袖表示，这样的疫苗可能为数百万人提供一种更简单、成本更低的选择。

　　这种损害大脑的疾病会导致思维和记忆问题。

　　美国政府网站ClinicalTrials.gov显示，至少有七种可能的阿尔茨海默症疫苗正在进行人体试验或已完成此类试验。这些实验性治疗方法旨在利用人体的自然防御系统来破坏大脑中与阿尔茨海默症相关的蛋白质。这些蛋白质是β淀粉样蛋白和tau蛋白。

　　对阿尔茨海默症疫苗的重新关注是在20多年前的一次有希望的初次尝试之后。那次疫苗研究在6%的研究志愿者出现了一种名为脑膜脑炎的威胁生命的大脑病症后停止。

　　然后，研究人员找到了一种在患者中使用精确靶向的合成抗体的更安全方法。这些抗体避免了极端的免疫系统反应。

　　医疗保健公司Eisai和Biogen推出了一种名为Leqembi的新药，医疗保健公司Eli Lilly推出了Donanemab。美国政府药物专家正在审查这些治疗方法。

　　这些药物的成功报道加强了清除淀粉样蛋白对抗阿尔茨海默症至关重要的理论。

　　科学家们认为他们现在已经理解了第一种疫苗出了什么问题。他们正在测试他们希望能引发免疫反应但不会引起过多炎症的疫苗。

　　Reisa Sperling博士是波士顿Mass General Brigham的阿尔茨海默症研究员。她表示，她相信在研究人员寻求预防阿尔茨海默症的过程中，疫苗将发挥重要作用。她说，“我非常热衷于我们需要走的方向。”

　　Sperling正在领导一项针对大脑中有阿尔茨海默症蛋白质但没有显示相关问题迹象的人的试验。她正在考虑在下一项研究中为那些血液中有阿尔茨海默症蛋白质，但不足以在大脑影像上显示的人接种疫苗。

　　阿尔茨海默症疫苗仍处于早期阶段，需要大规模、长期的试验来证明它们的效果。

　　但是，每年接种两次或四次的疫苗可能比Leqembi提供更低成本的解决方案。Leqembi每月需要使用两次。这可能扩大全球预计有3900万患有阿尔茨海默症的人的可用治疗范围。

　　Walter Koroshetz博士是美国国立卫生研究院负责处理涉及大脑的疾病部分的主任。他对疫苗说，“它们可以在全球范围内使用，而且并不那么昂贵。”

　　我是Gregory Stachel。

　　Julie Steenhuysen为路透社报道了这个故事。Gregory Stachel为美国之音学习英语改编了它。

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　　这个故事中的词汇：

　　synthetic – adj. 合成的，由不同物质组合而成的：非自然的

　　antibodies – n.体内产生的抵抗疾病的物质

　　immune system – n.保护身体免受疾病和感染的系统

　　inflammation – n.体内某部位变红、肿胀和疼痛的状况

　　keen – adj. 对某事非常兴奋和感兴趣

　　trial – n. 对某物的质量、价值或用途的测试