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你真的需要接种流感疫苗吗?

 东那个东 2012-11-12

THE CONSUMER

Reassessing Flu Shots as the Season Draws Near

It’s flu-shot season, and public health officials are urging everyone over 6 months of age to get one. Many businesses provide on-site flu shots, and some hospitals have told staff members that they have to wear masks if they do not get the vaccine. By 2020, United States health leaders want 80 percent of the population to get yearly shots.接种流感疫苗的季节到了,公共卫生的管理者们正在敦促所有年满6个月的人及时接种。不少公司在办公场所为员工注射疫苗,一些医院则通知员工,如果他们没有接种流感疫苗,就需要一直佩戴口罩。美国的卫生部门领导者希望,到2020年,有80%的人口每年定期接种流感疫苗。

For vaccine manufacturers, it’s a bonanza: Influenza shots — given every year, unlike many other vaccines — are a multibillion-dollar global business.对疫苗生产厂商来说,这是一座金矿:流感疫苗跟其他不少疫苗的不同之处在于,它是每年都要接种一次的,它是价值几十亿美元的跨国生意。

But how good are they?但流感疫苗究竟有多好呢?

Last month, in a step tantamount to heresy in the public health world, scientists at the Center for Infectious Disease Research and Policy at the University of Minnesota released a report saying that existing influenza vaccinations provide only modest protection for healthy young and middle-age adults, and little if any protection for those 65 and older, who are most likely to succumb to the illness or its complications. Moreover, the report’s authors concluded, federal vaccination recommendations, which have expanded in recent years, are based on inadequate evidence and poorly executed studies.上个月,公共卫生界就出现了一种不啻为异端的声音,明尼苏达大学(University of Minnesota)传染病研究和政策中心的科学家们发表了一篇论文称,流感疫苗仅对健康的中青年成人提供适度的保护,而对最有可能遭遇流感和其并发症攻击的65岁以上长者,提供的保护则微乎其微。这篇文章的几位作者还总结说,联邦疫苗接种推荐范围在近年来不断扩大,但它建立在不充分的证据和执行较差的调研上。

“We have overpromoted and overhyped this vaccine,” said Michael T. Osterholm, director of the Center for Infectious Disease Research and Policy, as well as its Center of Excellence for Influenza Research and Surveillance. “It does not protect as promoted. It’s all a sales job: it’s all public relations.”传染病研究和政策中心主任、兼流感研究及监测卓越中心主任迈克尔·T·奥斯特霍尔姆(Michael T. Osterholm)说:“对于流感疫苗,我们推广的力度过大、炒作过度了。它并不能像宣传的那样起到保护作用。它靠的全都是推销、全都是公关。”

Dr. Osterholm, who says he is concerned that confidence in current vaccines deters research into identifying more effective agents, comes from the world of public health and the Centers for Disease Control and Prevention. A bioterrorism and public health preparedness adviser to Tommy Thompson, the former health and human services secretary, he served on the interim management team during a transition period at the C.D.C. in 2002.奥斯特霍尔姆博士说,他担心由于公共卫生界和美国疾病控制和预防中心(Centers for Disease Control and Prevention)对现有疫苗的信心过了头,会导致厂商不再有动力去研发更有效的疫苗制剂。奥斯特霍尔姆担任前美国卫生和公共服务部部长汤米·汤普森(Tommy Thompson)的生物恐怖主义和公共卫生防备顾问,在2002年,曾在美国疾控中心处在过渡期时,在临时管理团队中任职。

“I’m an insider,” Dr. Osterholm said. “Until we started this project, I was one of the people out there heavily promoting influenza vaccine use. It was only with this study that I looked and said, ‘What are we doing?’ “我是内部人士,在我们启动了这项研究计划前,我始终在为推广接种流感疫苗大声疾呼。一直是到我看到研究论文时,我才开始追问,‘我们在做些什么啊?’”奥斯特霍尔姆说。

He still considers himself a “a pro-vaccine guy,” Dr. Osterholm said.不过他也表示,自己仍是“支持疫苗派”。

“I say, ‘Use this vaccine,’ ” he said. “The safety profile is actually quite good. But we have oversold it. Use it — but just know it’s not going to work nearly as well as everyone says.”“我会说,‘接种流感疫苗’。它的安全性确实很不错。但我们把它吹得太过了。你可以接种它——但你得知道,它并不会像大家说得那么灵。”他说。

While researching the report released last month, Dr. Osterholm said, the authors discovered a recurring error in influenza vaccine studies that led to an exaggeration of the vaccine’s effectiveness. They also discovered 30 inaccuracies in the statement on influenza vaccines put forth by the expert panel that develops vaccine recommendations, all of which favor the vaccine.奥斯特奥尔姆说,在对上个月发表的这篇论文进行调研时,研究作者们发现在流感疫苗的研究中出现了一个频繁发生的错误,导致疫苗的效用被夸大。他们还发现,撰写疫苗接种建议的专家组最后写成的流感疫苗说明中,出现了30处不准确的地方,这30处全部都是支持使用疫苗的。

C.D.C. officials acknowledge that the vaccines do not work as well in the elderly population as they do in younger healthy adults. But, they say, the effectiveness of the flu shots, which are reformulated every year in an attempt to match the strains most likely to be circulating that season, varies depending on the population being inoculated and the year.美国疾控中心的官员承认,流感疫苗对老年人的用处,不如对较年轻的健康成年人那么显著。不过他们认为,流感疫苗每年都会根据这一季最有可能流行哪种病毒而重新调整配方,因此其效用会随着接种人群的数量以及那一年的具体流感特点而有所不同。

“Does it work as well as the measles vaccine? No, and it’s not likely to. But the vaccine works,” Dr. Joseph Bresee, chief of epidemiology and prevention in the C.D.C.’s influenza division, said. And research is advancing to improve the effectiveness of the vaccine.美国疾控中心流感部门的流行病和预防主任约瑟夫·布雷西(Joseph Bresee)博士说:“流感疫苗能跟麻疹疫苗一样有用吗?不能,它也不可能做到这一点。但这种疫苗确实有用。”他还说,目前正在进行研究,希望能进一步提高流感疫苗的有效性。

Although the vaccine may be less effective at preventing influenza in the elderly, Dr. Bresee said, that is the population most susceptible to the disease and at highest risk. Anywhere from as few as 3,000 to as many as 49,000 Americans die of influenzaeach year, some 90 percent of them elderly.贝雷西说,尽管流感疫苗对老年人预防流感效果最不显著,但老年人也是最易患流感的高危人群。在美国,每年少则3000人,多则4.9万人死于流感,其中约有九成为老人。

The new report from the Center for Infectious Disease Research and Policy is not the first to point out the shortcomings of influenza vaccines, however. The Cochrane Collaboration, an international network of experts that evaluates medical research, concluded in a 2010 review that the vaccines decrease symptoms in healthy adults under 65 and save people about a half-day of work on average, but that they do not affect the number of people hospitalized and have minimal impact in seasons when vaccines and viruses are mismatched. (When the vaccine matches the circulating viruses, 33 adults need to be vaccinated to avoid one set of influenza symptoms; when there is only a partial match, 100 people must be vaccinated for the same effect.) It was also concluded that the vaccines appear to have no effect on hospital admissions, transmission or rates of complications. A separate Cochrane review on vaccines for the elderly determined the evidence was so scant and of such poor quality that it could not provide guidance. Dr. Bresee of the C.D.C. pointed to only one randomized controlled trial of influenza vaccine in older people, and it looked at people age 60 and over in the Netherlands healthy enough to not be hospitalized or in a nursing home.传染病研究和政策中心的这份新研究报告,并不是针对流感疫苗缺陷所出现的第一份报告。考克兰协作网(Cochrane Collaboration)是一个汇集全球专家评估医学研究的网络,2010年该网络在一篇论文中总结说,对于65岁以下的健康成年人,流感疫苗可以缓解他们的症状,平均能减少半天的病休时间,但这种疫苗并不会影响因流感而住院的人数,此外如果疫苗与病毒匹配有误,其作用将降至最低。(如果疫苗匹配了当季的流行优势病株,每注射免疫33个成年人,能有效预防一例流感;可是如果疫苗只是部分匹配,想要产生同样的效果就需要有100人接种。)这篇论文还总结说,流感疫苗看来对入院人次、流感传播或并发症发生机率并无影响。此外,考克兰协作网回顾了老年人接种疫苗的文献后认为,相关证据十分不足,而且质量低劣,不足以提供指导。疾控中心的布雷西博士也表示,目前对于流感疫苗在年长者身上所起到的作用,只进行过一次随机对照试验,而且这项实验针对的是荷兰60岁以上老年人,这些老人本身身体健康,都未住院治疗或住在养老院中。

Another Cochrane review found no evidence that vaccinating health care workers who work with the elderly has any effect on influenza or pneumonia deaths.考克兰协作网的另一份研究表明,并未发现证据证明,给那些向长者提供医疗服务的医护人员接种疫苗,会对长者因流感或肺炎而死亡产生任何影响。

“Not having evidence doesn’t prove it doesn’t work; we just don’t know,” said Dr. Roger Thomas, a Cochrane Collaboration coordinator for the University of Calgary in Alberta, who was an author of both of the reviews. “The intelligent decision would be to have large, publicly funded independent trials.”罗杰·托马斯(Roger Thomas)博士是考克兰协作网在加拿大卡尔加里大学(University of Calgary)的协调人,也是上述两篇论文的作者之一,他说:“没有证据并不说明它一点用都没有;我们只是不能确切了解而已 。明智之举是由政府出资,进行大型的独立试验。”

But those may never be conducted on the elderly, in large part because of the way the vaccine was promulgated. Initially developed for soldiers and approved in 1945, the vaccine was approved for civilian use a year later. In 1960, the surgeon general, Leroy E. Burney recommended vaccinating three high-risk groups: pregnant women, the chronically ill and people 65 and over, Dr. Osterholm said. Once that recommendation was made, scientists felt that it would be unethical to run a trial that would essentially deny a recommended vaccine to participants assigned to the placebo group.但这种实验恐怕永远也不可能在老年人口中展开,其中很大一部分原因在于流感疫苗被推广的方式。据奥斯特霍尔姆介绍,流感疫苗在1945年首次被研发并审批通过,当时只适用于军人,次年获得批准开始在平民中接种。1960年,军医处处长勒罗伊·E·伯尼(Leroy E. Burney)推荐将流感疫苗用于三个高危人群,分别是孕妇、慢性病患者和65岁以上老人。一旦做出了这种接种推荐,科学家们难免觉得,如果进行一项试验,分到安慰剂组的参与者实则上会被剥夺使用推荐疫苗的权利,这种做法是不道德的。

C.D.C. officials say population-based studies show that elderly people who get flu shots are less likely to die of any cause than elderly people who do not get them. Critics say these studies suffer from what’s called the healthy vaccine recipient effect and prove only that older people who are in good health and take care of themselves go to the doctor regularly — and get flu shots.疾控中心的官员们说,基于人群的研究表明,接种了流感疫苗的老人相比没有接种的老人,死于各种疾病的机率相对都较低。对此,批评者反唇相讥,指出这些研究出现了所谓的“健康疫苗接种者效应”,研究只能证明那些老人身体状况良好,而且重视身体健康,定期去看医生并接种疫苗。

Many of these are big-picture concerns that an individual patient cannot do much about. The reassuring news is that even critics of the influenza vaccines agree that serious complications are rare.上述这些担忧着眼的都是大规模人口,单个的患者很难对此做出什么反应。不过令人安慰的是,即使是流感疫苗的批评人士也认同,这类疫苗导致的严重并发症极其罕见。

Another option for those who want to reduce their risk of influenza and flulike infections may be simply this: Wash your hands more often. There is good evidence this works.对于那些想要避免患上流感或类似传染病的人来说,除了接种疫苗还有一个相当简单易行的办法:勤洗手。有不少证据证明,这一招真的管用。

E-mail: consumer@.本文最初发表于2012年11月6日。

翻译:Noey

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