美泰两国研制出艾滋病“准疫苗”(组图)

http://tech.QQ.com　 2009年09月28日07:40 　 新华报业网-扬子晚报　 　

图：艾滋病毒在电子显微镜下的图像

艾滋病病毒和人体淋巴细胞接触的瞬间

2009年1月20日在泰国一家医院中拍下的艾滋病感染者

“重大成果”、“历史性突破”、“里程碑”……众多溢美之词,在24日铺天盖地蜂拥向一项科研成果:美国和泰国研究人员24日联合宣布,一种新型试验疫苗可使人体感染艾滋病病毒的风险降低31.2%。这是世界上第一种具有一定免疫效果的艾滋病疫苗。尽管其免疫效果还很有限,但它实现了“免疫效果”从无到有的跨越,给人类抗击艾滋病这一“世纪瘟疫”带来了新希望。

“联合疫苗”由两种疫苗组成

这一名为RV144的项目由美国军方、泰国公共卫生部等机构联合于2003年开始实施。

研究人员24日介绍说,这种“联合疫苗”是由两种疫苗组成的,其中一种负责刺激免疫系统,使其做好攻击艾滋病病毒的准备;第二种则担当“助攻手”,负责增强免疫反应。但此前的试验显示,这两种疫苗独立使用均无效果。

“联合疫苗”试验始于2003年10月,试验对象是在泰国选取的1.6万多名年龄在18岁至30岁的志愿者。其艾滋病病毒检测均为阴性,且其感染风险与普通人群的平均水平相当。其中,一组志愿者被注射了“联合疫苗”,另一对照组则只被注射了安慰剂。结果显示,在8197名接受疫苗注射的志愿者中,51人感染了艾滋病病毒,而在对照组的8198人中,有74人感染,即注射疫苗组感染风险降低了31.2%。

美国陆军军医处处长埃里克·斯库梅克说,这是“第一个备选艾滋病疫苗成功减少艾滋病感染危险”的实例。

“虽然免疫效果有限,但在统计学上显示出降低艾滋病病毒感染风险的重要意义,”法国赛诺菲-巴斯德公司研发副总裁米歇尔·德维尔德说,“自从1983年发现艾滋病病毒以来,这是科学界首次获得具体证据证明,研发艾滋病疫苗是可行的。”

为抗击艾滋病带来希望

客观而言,一种疫苗具有降低不足三分之一感染风险的免疫效果,远未达到可以大规模进入临床应用的标准,但其重要意义在于,它驱散了人类在艾滋病疫苗研究领域长期踯躅不前的阴霾,给人们带来了成功抗击艾滋病的新希望。

科学界早已认识到,研制疫苗是抗击艾滋病病毒最为有效的良方。但在人类发现艾滋病病毒后的近30年里,科学界进行了数十种疫苗的临床试验,数万名志愿者参与了试验,但所有研究都以失败告终,甚至一度使得有些科学家认为,人类可能永远都找不到一种有效的艾滋病疫苗。此前美国默克公司一项原本被寄予厚望的研究无果而终,被医学界称为“灾难性的失败”,极大打击了研究者的信心。

而此次研究成果给了研究人员重新乐观的理由。世界卫生组织和联合国艾滋病规划署当天发表联合声明表示,这一代表重大科学进步的试验结果首次表明,通过疫苗是可以在普通成年人中预防感染艾滋病病毒的,其意义重大。

据统计,目前每天新增的艾滋病病毒感染人数多达7500人。由此可见,在艾滋病疫苗研究领域的点滴进展都令人兴奋。而这一成果表明,成功研发出有效的艾滋病疫苗完全可能,人类击败“世纪瘟疫”大有希望。

目前还不能批准生产

不过,冷静分析此项成果可以看到许多疑问。例如,针对不同的艾滋病病毒,针对不同人群,新型疫苗是否都有相同的免疫效果?新型疫苗的有效免疫期有多久?新型疫苗为何只表现出有限的免疫效果?

包括联合国艾滋病规划署、世界卫生组织等机构也都表示“谨慎的乐观”。世界卫生组织和联合国艾滋病规划署的联合声明指出,仅仅基于目前的试验结果,还不能批准生产这种疫苗,因为还需要进一步研究确认这种疫苗对世界其他地方的人群是否能产生同样的免疫效果。声明还强调说,就目前的试验结果看,这种疫苗只能是一种辅助手段,还不能完全取代预防艾滋病的其他措施。

研究人员说,这种疫苗针对的是泰国流行的艾滋病病毒,是否对美国、非洲或其他地区流行的艾滋病病毒有效现在还不清楚。另外，研究人员眼下还不十分清楚这种疫苗如何能降低艾滋病感染几率。

The United States and Thailand have developed AIDS, the two "quasi-vaccine" (Photos)
http://tech.QQ.com 2009 Nian 09 Yue 28 Ri 07:40 The Associated Press - Yangzi Evening News
  Photo Week: inventory of the animal world, "cross-species" of the emotions (Photos)



Chart: HIV in the electron microscope images of

AIDS virus and human lymphocytes in contact with an instant

January 20, 2009 in Thailand and photographed in a hospital AIDS


"Significant results", "historic breakthrough", "milestone" ... ... many words of praise, at 24, an overwhelming rush to the research results: the United States and Thailand, researchers announced on the 24th, a new type of test vaccine will enable the human body reduce the risk of HIV infection 31.2%. This is the world's first have a certain effect of AIDS vaccine immunization. Despite its immune effect is still very limited, but it achieved a "immunization effect" from scratch by leaps and bounds, to human beings to fight AIDS, this "plague of the century," has brought new hope.

"Combined vaccine" by two kinds of vaccines composed of

The project, called RV144 by the U.S. military, the Thai Ministry of Public Health and other institutions was implemented in 2003.

24, said the researchers, this "vaccine" is composed by two kinds of vaccines, one of which is responsible for stimulating the immune system to attack the AIDS virus do to prepare; the second would take the "assists hand" is responsible for enhanced immune response. However, previous tests have shown that there was no effect of the two vaccines used independently.

"Combined vaccine" trial began in October 2003 the test object is selected in Thailand, more than 16000 aged 18 to 30-year-old volunteers. Of their HIV test were negative, and its risk of infection with the average level of the general population rather. Among them, a group of volunteers have been injected with a "combination vaccine" and the other control group was injected with a placebo only. The results showed that in 8197 vaccinated volunteers, 51 people were infected with HIV, while in the control group of 8198 people, 74 people infected, or vaccinated group 31.2% lower risk of infection.

U.S. Army surgeon general Eric Peter J. Schoomaker said it was "the first AIDS vaccine candidate successful in reducing risk of HIV infection," examples.

"Although the immune effect is limited, but statistically shown to reduce the risk of HIV infection in the importance of the" French Sanofi - Pasteur, Michel De Wilde, vice president of research and development, said, "Since the discovery of HIV in 1983 Since this is the first time the scientific community to obtain concrete evidence to the development of an AIDS vaccine is feasible. "

Bring hope to the fight against AIDS

Objectively speaking, a vaccine to reduce the risk of infection less than one-third of the immune effects, far from clinical application can be a large-scale access to standards, but its significance lies in the fact that it broke up the field of human AIDS vaccine research the long-term wander not pre-haze, gave rise to new hope for the success of the fight against AIDS.

The scientific community has long recognized that development of a vaccine against HIV is the most effective remedy. But the discovery of AIDS virus in humans nearly 30 years, the scientific community for several dozens of vaccine clinical trials, tens of thousands of volunteers participated in the pilot, but all the studies have ended in failure, and even once led some scientists believe that human beings may never find an effective AIDS vaccine. Prior to the U.S. Merck & Co., one of the original hope was fruitless, the medical profession has been called the "catastrophic failure", a great blow to the confidence of the researchers.

The results of this study to the researchers to re-reason for optimism. World Health Organization and UNAIDS issued a joint statement the same day, the representatives of major scientific advances of the test results for the first time that vaccine can prevent infection in the general adult population with HIV, and its great significance.

According to statistics, the current daily number of new HIV infections up to 7500 people. This shows that in the field of AIDS vaccine research bit by bit progress has been exciting. And this results indicate that successfully developed an effective HIV vaccine may well, human beat "century plague" promising.

Not currently approved for production

However, the cool-headed analysis of the results can see a number of questions. For example, for different HIV, for different groups of people, the new vaccine has the same immune effect? New vaccines and effective immune period is how long? Why a new vaccine has shown only limited immune effect?

Including UNAIDS, WHO and other agencies have expressed "cautious optimism." World Health Organization and UNAIDS joint statement said that based only on the current test results, it could not approve the production of this vaccine, because further studies are needed to confirm this vaccine to the rest of the world population is able to produce the same immune effect . The statement also stressed that the test results on the current view, this vaccine can only be a supplementary tool, it can not completely replace other measures to prevent AIDS.

The researchers said the vaccine against the HIV epidemic in Thailand, whether the United States, Africa or other parts of an effective HIV epidemic is unclear. In addition, the researchers now are not very clear how the vaccine can reduce the risk of HIV infection.