美国国家公共电台 NPR--The FDA considers a major shift in the nation's COVID vaccine strategy

The FDA considers a major shift in the nation's COVID vaccine¹ strategy

Transcript²

The Food and Drug Administration is considering a major shift in the nation's COVID-19 vaccine strategy.

The goal is to simplify vaccination³ against COVID and perhaps adopt an approach similar to what is used for the flu vaccine, with annual updates to match whatever strain of the virus is circulating. This is according to a federal official who spoke⁴ under the condition of anonymity⁵ because they were not authorized⁶ to speak publicly.

NPR reported the proposed shift early Monday morning, and later Monday the FDA outlined it publicly in a set of documents released in advance of a meeting Thursday of the agency's Vaccine and Related Biological Products Advisory⁷ Committee (VRBPAC). The committee will vote on the agency's proposal.

Currently, people who want to be fully⁸ vaccinated⁹ against COVID have to first get their primary vaccinations¹⁰ — two shots of the original vaccine spaced weeks apart. That's followed at least two months later by a booster, currently the bivalent shot that's tailored to protect against omicron.

Under the new approach, most people would be advised to simply get whatever the latest version of the vaccine is annually¹¹ each fall like the flu vaccine. They wouldn't have to worry about how many shots they've already gotten and which one they got when. Those who still need to receive two doses initially¹², such as young children and older people, would use the same formulation for all three shots.

Vaccine makers¹³ would update the annual shot through a process that would begin each spring to try a match the vaccine as closely as possible to whatever variant¹⁴ will likely be dominant¹⁵ in the coming winter. That's how the flu vaccine is formulated¹⁶ each year.

"FDA anticipates conducting an assessment¹⁷ of SARS-CoV-2 strains at least annually and to engage VRBPAC in about early June of each year regarding strain selection for the fall season," the FDA wrote in its briefing document, adding that updated vaccines¹⁸ would be readied for use by September each year.

The agency notes that if a more dangerous COVID variant were to emerge, it might reconsider the vaccine strain at other times of the year on an "as-needed and emergent basis."

Some immunologists and vaccine researchers say simplifying the process along the lines of the flu vaccine is appropriate at this point in the pandemic. However, many questions remain about emerging booster strategy.

"As far as the tools that we have right now, I think it just makes the most sense to plan to update each year as close as we can to the currently circulating variant," says Deepta Bhattacharya, an immunologist at the University of Arizona. "So I think all the things the FDA is considering make a lot of sense."

Questions about efficacy of updated shots

There's an intense debate about the wisdom of updating the COVID vaccines regularly to try to match new variants¹⁹. Some researchers question whether that really makes the vaccines more effective. They also argue that the low demand for the latest booster shows the public has little appetite for continued boosting with the vaccines, even if they've been updated with new strains.

"The public is voting with their arms if you will and said, 'No. I'm not going to get this. This doesn't make sense to us,'" says Dr. Gregory Poland, a vaccine researcher at the Mayo Clinic.

While endorsing²⁰ continued boosters for those at high risk, such as the elderly, some question whether the current bivalent vaccines updated to target omicron have enhanced protection compared to the original vaccines. Most people are still well-protected against severe disease by the immunity²¹ they already have, they say.

"We have no solid data about the performance of the bivalent boosters," says John Moore, an immunologist at Weill Cornell Medical College. "The hard evidence is lacking, and the evidence that is out there is at the very least inconclusive and to me trends towards saying the bivalent boosters were little if no better."

Moore and others argue that the virus is changing so fast that it's pointless to constantly try to match the vaccines to the latest variants.

"We shouldn't really be chasing these variants, which are evanescent and are often gone by the time you've created the vaccine," says Dr. Paul Offit of the University of Pennsylvania, one of the FDA's advisers²².

Offit and others also question whether everyone will necessarily need to be boosted regularly, or just those at high risk, like the elderly.

Arguments for alternate vaccine strategies

Critics of the FDA's proposed new strategy argue that it would be better to invest in developing better vaccines that might be more appealing to people, and in campaigns to get more people vaccinated. Better vaccines could include those that could keep people from catching²³ the virus in the first place not just from getting seriously ill — such as a nasal spray vaccine. Or perhaps vaccines that provide longer protection or are administered in pill form, to make them more acceptable to the needle-averse.

"Particularly now when Congress is not allocating²⁴ new funds for COVID response, we have to be especially judicious²⁵ in how we spend our money and what would be most cost-effective," says Dr. Celine Gounder, a senior fellow at the Kaiser Family Foundation. "It's unclear whether updating the booster formulations and repeatedly boosting people is the most effective approach to controlling COVID at this stage."

Another concern some researchers have is that the FDA continues to rely on antibody levels to test vaccine efficacy.

"I think we need to raise the bar and require more evidence of clinical efficacy," says Dr. Eric Rubin, a professor of immunology and infectious diseases at Harvard who is also a member of the advisory committee. For instance, Rubin says the FDA should require proof the updated vaccines are actually reducing the risk of getting infected, getting sick, hospitalized and dying.

Others say updating the vaccines make sense to make sure people are as well-protected as possible while researchers continue to try to develop new vaccines.

"Even if you don't have a booster that matches 100% what's circulating, you will have a booster that matches 75% to 80% to 90% of what's circulating," says David Martinez, an immunologist at the University of North Carolina, Chapel²⁶ Hill. "And that will be good enough. It would probably benefit most people."

The FDA looks ahead to endemic COVID

Some researchers think it's too soon to rely on annual boosters. COVID hasn't quite settled into a seasonal²⁷ pattern like the flu, they note, and the SARS-CoV2 virus is changing more quickly than the flu virus. So people may need to be boosted more frequently, especially since protection against severe disease may only last about four to six months, they say.

"We're going to be reaching that pretty soon with the early adopters of the bivalent boosters, like myself," says Dr. Peter Hotez, co-director of the Center for Vaccine Development at Texas Children's Hospital and dean of the National School of Tropical Medicine at Baylor College of Medicine. "I don't know if an annual strategy is going to cut it."

The FDA's plan comes as COVID appears to be moving toward becoming an endemic disease. That doesn't mean it's going away or it's not a threat anymore. The disease will continue to be a threat for the foreseeable future, making many people sick and even potentially killing²⁸ hundreds a day, making it a major public health problem and a leading cause of death, health experts say.

But unless some more dangerous version of the virus suddenly emerges, the world might finally be settling into a more predictable co-existence with the virus. The federal official NPR spoke to says the goal of the new vaccine strategy is to make the vaccines, which are the major weapon for protecting ourselves, simpler and hopefully therefore more appealing. The latest boosters have found very few takers.

The thinking is that at this point in the pandemic the overwhelming majority of people have a significant levels of immunity, either from having gotten vaccinated and boosted, or infected one of more times, or both. And while that immunity appears to protect most people from severe disease, that protection does appear to fade with time.

The FDA is also considering making the shots interchangeable. That way people wouldn't have to worry which brand they're getting. Again, the change is aimed at making COVID shots more like the flu shots. People don't typically worry about the brand of the flu vaccine they receive.

The vaccine would still be administered at different doses for different ages. And very young children and older people would still get two shots each year, much like the flu vaccine.

If the FDA advisory committee endorses²⁹ the approach Thursday, the FDA would work with the vaccine companies and Centers for Disease Control and Prevention to finalize³⁰ the details. And the FDA advisers would meet again in the spring to pick the specific strain or strains of the virus the new shots should target.

1 vaccine   

n.牛痘苗，疫苗；adj.牛痘的，疫苗的

参考例句：

• The polio vaccine has saved millions of lives.脊髓灰质炎疫苗挽救了数以百万计的生命。
• She takes a vaccine against influenza every fall.她每年秋季接种流感疫苗。

2 transcript   

n.抄本，誊本，副本，肄业证书

参考例句：

• A transcript of the tapes was presented as evidence in court.一份录音带的文字本作为证据被呈交法庭。
• They wouldn't let me have a transcript of the interview.他们拒绝给我一份采访的文字整理稿。

3 vaccination   

n.接种疫苗，种痘

参考例句：

• Vaccination is a preventive against smallpox.种痘是预防天花的方法。
• Doctors suggest getting a tetanus vaccination every ten years.医生建议每十年注射一次破伤风疫苗。

4 spoke   

n.（车轮的）辐条；轮辐；破坏某人的计划；阻挠某人的行动 v.讲，谈（speak的过去式）；说；演说；从某种观点来说

参考例句：

• They sourced the spoke nuts from our company.他们的轮辐螺帽是从我们公司获得的。
• The spokes of a wheel are the bars that connect the outer ring to the centre.辐条是轮子上连接外圈与中心的条棒。

5 anonymity   

n.the condition of being anonymous

参考例句：

• Names of people in the book were changed to preserve anonymity. 为了姓名保密，书中的人用的都是化名。
• Our company promises to preserve the anonymity of all its clients. 我们公司承诺不公开客户的姓名。

6 authorized   

a.委任的，许可的

参考例句：

• An administrative order is valid if authorized by a statute.如果一个行政命令得到一个法规的认可那么这个命令就是有效的。

7 advisory   

adj.劝告的，忠告的，顾问的，提供咨询

参考例句：

• I have worked in an advisory capacity with many hospitals.我曾在多家医院做过顾问工作。
• He was appointed to the advisory committee last month.他上个月获任命为顾问委员会委员。

8 fully   

adv.完全地，全部地，彻底地；充分地

参考例句：

• The doctor asked me to breathe in,then to breathe out fully.医生让我先吸气，然后全部呼出。
• They soon became fully integrated into the local community.他们很快就完全融入了当地人的圈子。

9 vaccinated   

[医]已接种的，种痘的，接种过疫菌的

参考例句：

• I was vaccinated against tetanus. 我接种了破伤风疫苗。
• Were you vaccinated against smallpox as a child? 你小时候打过天花疫苗吗？

10 vaccinations   

n.种痘，接种( vaccination的名词复数 )；牛痘疤

参考例句：

• Vaccinations ensure one against diseases. 接种疫苗可以预防疾病。 来自《简明英汉词典》
• I read some publicity about vaccinations while waiting my turn at the doctor's. 在医生那儿候诊时，我读了一些关于接种疫苗的宣传。 来自《简明英汉词典》

11 annually   

adv.一年一次，每年

参考例句：

• Many migratory birds visit this lake annually.许多候鸟每年到这个湖上作短期逗留。
• They celebrate their wedding anniversary annually.他们每年庆祝一番结婚纪念日。

12 initially   

adv.最初，开始

参考例句：

• The ban was initially opposed by the US.这一禁令首先遭到美国的反对。
• Feathers initially developed from insect scales.羽毛最初由昆虫的翅瓣演化而来。

13 makers   

n.制造者，制造商（maker的复数形式）

参考例句：

• The makers of the product assured us that there had been no sacrifice of quality. 这一产品的制造商向我们保证说他们没有牺牲质量。
• The makers are about to launch out a new product. 制造商们马上要生产一种新产品。 来自《简明英汉词典》

14 variant   

adj.不同的，变异的；n.变体，异体

参考例句：

• We give professional suggestions according to variant tanning stages for each customer.我们针对每位顾客不同的日晒阶段，提供强度适合的晒黑建议。
• In a variant of this approach,the tests are data- driven.这个方法的一个变种，是数据驱动的测试。

15 dominant   

adj.支配的，统治的；占优势的；显性的；n.主因，要素，主要的人(或物)；显性基因

参考例句：

• The British were formerly dominant in India.英国人从前统治印度。
• She was a dominant figure in the French film industry.她在法国电影界是个举足轻重的人物。

16 formulated   

v.构想出( formulate的过去式和过去分词 )；规划；确切地阐述；用公式表示

参考例句：

• He claims that the writer never consciously formulated his own theoretical position. 他声称该作家从未有意识地阐明他自己的理论见解。 来自《简明英汉词典》
• This idea can be formulated in two different ways. 这个意思可以有两种说法。 来自《现代汉英综合大词典》

17 assessment   

n.评价；评估；对财产的估价，被估定的金额

参考例句：

• This is a very perceptive assessment of the situation.这是一个对该情况的极富洞察力的评价。
• What is your assessment of the situation?你对时局的看法如何？

18 vaccines   

疫苗，痘苗( vaccine的名词复数 )

参考例句：

• His team are at the forefront of scientific research into vaccines. 他的小组处于疫苗科研的最前沿。
• The vaccines were kept cool in refrigerators. 疫苗放在冰箱中冷藏。

19 variants   

n.变体( variant的名词复数 )；变种；变型；（词等的）变体

参考例句：

• Those variants will be preserved in the'struggle for existence". 这些变异将在“生存竞争”中被保留下来。 来自辞典例句
• Like organisms, viruses have variants, generally called strains. 与其他生物一样，病毒也有变种，一般称之为株系。 来自辞典例句

20 endorsing   

v.赞同( endorse的现在分词 )；在（尤指支票的）背面签字；在（文件的）背面写评论；在广告上说本人使用并赞同某产品

参考例句：

• Yet Communist leaders are also publicly endorsing religion in an unprecedented way. 不过，共产党领导层对宗教信仰的公开认可也是以前不曾有过的。 来自互联网
• Connecticut Independent Senator Joseph Lieberman is endorsing Republican Senator John McCain. 康涅狄格州独立派参议员约瑟夫。列波曼将会票选共和议员约翰。麦凯恩。 来自互联网

21 immunity   

n.优惠；免除；豁免，豁免权

参考例句：

• The law gives public schools immunity from taxation.法律免除公立学校的纳税义务。
• He claims diplomatic immunity to avoid being arrested.他要求外交豁免以便避免被捕。

22 advisers   

顾问，劝告者( adviser的名词复数 )； （指导大学新生学科问题等的）指导教授

参考例句：

• a member of the President's favoured circle of advisers 总统宠爱的顾问班子中的一员
• She withdrew to confer with her advisers before announcing a decision. 她先去请教顾问然后再宣布决定。

23 catching   

adj.易传染的，有魅力的，迷人的，接住

参考例句：

• There are those who think eczema is catching.有人就是认为湿疹会传染。
• Enthusiasm is very catching.热情非常富有感染力。

24 allocating   

分配，分派( allocate的现在分词 )； 把…拨给

参考例句：

• Administrative practice generally follows the judicial model in allocating burdens of proof. 在分配举证责任方面，行政实践通常遵循司法模式。
• A cyclical multiplexing technique, allocating resources in fixed-time slices. 以固定的时间片分配资源的循环复用技术。

25 judicious   

adj.明智的，明断的，能作出明智决定的

参考例句：

• We should listen to the judicious opinion of that old man.我们应该听取那位老人明智的意见。
• A judicious parent encourages his children to make their own decisions.贤明的父亲鼓励儿女自作抉择。

26 chapel   

n.小教堂，殡仪馆

参考例句：

• The nimble hero,skipped into a chapel that stood near.敏捷的英雄跳进近旁的一座小教堂里。
• She was on the peak that Sunday afternoon when she played in chapel.那个星期天的下午，她在小教堂的演出，可以说是登峰造极。

27 seasonal   

adj.季节的，季节性的

参考例句：

• The town relies on the seasonal tourist industry for jobs.这个城镇依靠季节性旅游业提供就业机会。
• The hors d'oeuvre is seasonal vegetables.餐前小吃是应时蔬菜。

28 killing   

n.巨额利润；突然赚大钱，发大财

参考例句：

• Investors are set to make a killing from the sell-off.投资者准备清仓以便大赚一笔。
• Last week my brother made a killing on Wall Street.上个周我兄弟在华尔街赚了一大笔。

29 endorses   

v.赞同( endorse的第三人称单数 )；在（尤指支票的）背面签字；在（文件的）背面写评论；在广告上说本人使用并赞同某产品

参考例句：

• There isn't one country in the Middle East that now endorses the Eisenhower Doctrine. 但至今没有一个中东国家认可它。 来自辞典例句
• Whether any of this truly endorses Dr Patel's hypothesis is moot. 这些视频能否真正证明帕特的假设成立还是个未知数。 来自互联网

30 finalize   

v.落实，定下来

参考例句：

• Let us finalize tonight.让我们今天晚上干完
• 。At the same time,industrial designers work with engineers to finalize components and assembly.同时，工业设计师和工程师一道来完成部件和组装部分的工作。