VOA标准英语2010年-In Cameroon, TB Vaccine Breakthrough E

Deaths from tuberculosis¹ are increasing in the developing world and especially in Africa. It's the world's second deadliest infectious disease after HIV/AIDS. In 2008, nearly two million people died of TB and researchers warn that mortality rates will surge further if new drugs and vaccines³ are not developed.
Linda is a 35-year-old Cameroonian mother of two. She's one of 35.000 people in the country diagnosed every year with tuberculosis, which kills some 7,000. Her problem is compounded by the fact that she's also infected with HIV, the virus that causes AIDS:
X-ray of patient with tuberculosis"It is very difficult," she said. "Several times, I consider suicide but then I think about my children and want to be there for them. I have had TB for several years and despite all the drugs, I am still ill. The doctor says my problem is severe because I also have HIV. I have to take countless⁴ numbers of medicines every day and sometimes I just can't stand it."Like others in her condition, Linda longs for the day when an effective remedy will be found.
In early October, more than 200 researchers met for an international symposium⁵ in the Cameroonian capital, Yaounde. They discussed the disease, but had no new drugs or vaccines to report. They could only talk about new ways to improve existing treatments.
The meeting was hosted by the Novartis Institute for Tropical Diseases, a non-profit research organization trying to find new medicines for the treatment of neglected, infectious diseases like TB, malaria⁶ and Dengue fever.
One of the conference participants, Prof. Barry Clifton of the US National Institutes of Health, says the absence of new drugs is steadily⁷ increasing the number of deaths from TB:
"I don't feel very optimistic about a breakthrough any time in the foreseeable future unless people put more effort and emphasis and research into tackling TB," he said. "At our current level, I think we'll keep the pace to the point where we hopefully don't have many people who don't have any options. But we're not going to win the race."The only available vaccine² for TB, known as Bacille-Calmette-Guerin (BCG) was developed almost 90 years ago. It's a live vaccine similar to the TB bacterium⁸ and has been improved over the years to provide immunity⁹ with the first dose.
But while it reduces risks of severe forms of TB in early childhood, it is not very effective in adults, who can be infected even if they were vaccinated¹⁰ in their youth. And BCG is not safe for children with HIV because it can spur the onset¹¹ of the disease in those with weakened immune systems. Across Africa, most children are given the vaccine without knowledge of their HIV status.
The Link Between HIV and TBProf. Paul Herrling is head of the Novartis Institutes for Developing World Medical Research. He says there are a number of reasons for the current dilemma¹²:
"The first one is that the last medicines that we had for TB are about 40 years old, and one thing that people did not know at that time is that this is a very clever bacterium and when they're treated with the same medicines for a long time, they learn to escape it. That's what we call resistance."Scientists say TB strains can vary from multi-drug resistant¹³ (MDR-TB) to extensively drug resistant (XDR-TB).
The most prominent way the TB virus gains resistance is in patients' failing to complete their treatments.
Researchers say fighting tuberculosis is made more difficult by the increasing number of people, especially in Africa, like Linda, who are also infected with HIV. Prof. Christopher Kuaban of the University of Yaounde in Cameroon says HIV/AIDS patients are up to 20 times more likely to develop TB than people without HIV:
"HIV is an infection that destroys your immune system. TB is contained by this immune system – so if your immune system breaks down when you're infected by TB, the TB germ has nothing to fear because there's nobody to destroy it. That's why in any country where HIV is common, TB becomes very common."Ongoing¹⁴ research inconclusiveCurrent treatment is cumbersome¹⁵: it takes six to nine months and patients must take several tablets several times a day. Research in several parts of the world is focusing on developing treatment that's easier for the patient, as well as vaccines that may replace BCG.
Clinical trials are about to begin on one vaccine candidate -- called AERAS-422. They will be conducted in Kenya, South Africa, Uganda and India by the non-profit research organization Aeras Global TB Vaccine Foundation. It recently obtained a $785,000 three-year-grant from the US Food and Drug Administration. Officials say the results may be available by the year 2020.
Funding is a problem say researchers like Barry Clifton:
"A normal pharmaceutical¹⁶ company will take a hundred people working for several years to get a candidate to put into clinical trials. With TB, we don't have those kinds of resources because it's a developing world disease, and there's no financial incentive¹⁷. So, we try to do the best we can with the small resources we have. It's market-driven, so the big pharmaceutical companies are responsible for making money [for their shareholders]."Meantime, the epidemic¹⁸ continues to grow, especially in Africa, where cities are increasingly crowded; where poor people find little to eat to bolster¹⁹ their immune systems and where healthcare services are not adequate.
As a result, more and more people like Linda and her children are victims of stigma²⁰ and discrimination. They are increasingly turning their backs on hospitals and heading for traditional healers and proliferating²¹ prayer churches for help.
TB's Intimidating²² ComplexitiesTB is caused by a bacterium known as the Mycobacterium tuberculosis. It's spread from person to person through tiny airborne droplets²³ of infected sputum. It can affect almost any tissue or organ in the body, with the most common site being the lungs. Basically, it cripples the human immune system, leaving patients vulnerable to deadly bacterial²⁴ infection.
The WHO says of the nine million people diagnosed with TB worldwide last year, a third live in Africa. It's currently the leading cause of death among people with HIV/AIDS on the continent.

1 tuberculosis   

n.结核病，肺结核

参考例句：

• People used to go to special health spring to recover from tuberculosis.人们常去温泉疗养胜地治疗肺结核。
• Tuberculosis is a curable disease.肺结核是一种可治愈的病。

2 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。

3 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。

4 countless   

adj.无数的，多得不计其数的

参考例句：

• In the war countless innocent people lost their lives.在这场战争中无数无辜的人丧失了性命。
• I've told you countless times.我已经告诉你无数遍了。

5 symposium   

n.讨论会，专题报告会；专题论文集

参考例句：

• What have you learned from the symposium?你参加了这次科学讨论会有什么体会？
• The specialists and scholars present at the symposium come from all corners of the country.出席研讨会的专家学者们来自全国各地。

6 malaria   

n.疟疾

参考例句：

• He had frequent attacks of malaria.他常患疟疾。
• Malaria is a kind of serious malady.疟疾是一种严重的疾病。

7 steadily   

adv.稳定地；不变地；持续地

参考例句：

• The scope of man's use of natural resources will steadily grow.人类利用自然资源的广度将日益扩大。
• Our educational reform was steadily led onto the correct path.我们的教学改革慢慢上轨道了。

8 bacterium   

n.(pl.)bacteria 细菌

参考例句：

• The bacterium possibly goes in the human body by the mouth.细菌可能通过口进入人体。
• A bacterium is identified as the cause for his duodenal ulcer.一种细菌被断定为造成他十二指肠溃疡的根源。

9 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。

10 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？

11 onset   

n.进攻，袭击，开始，突然开始

参考例句：

• The drug must be taken from the onset of the infection.这种药必须在感染的最初期就开始服用。
• Our troops withstood the onset of the enemy.我们的部队抵挡住了敌人的进攻。

12 dilemma   

n.困境，进退两难的局面

参考例句：

• I am on the horns of a dilemma about the matter.这件事使我进退两难。
• He was thrown into a dilemma.他陷入困境。

13 resistant   

adj.(to)抵抗的，有抵抗力的

参考例句：

• Many pests are resistant to the insecticide.许多害虫对这种杀虫剂有抵抗力。
• They imposed their government by force on the resistant population.他们以武力把自己的统治强加在持反抗态度的人民头上。

14 ongoing   

adj.进行中的，前进的

参考例句：

• The problem is ongoing.这个问题尚未解决。
• The issues raised in the report relate directly to Age Concern's ongoing work in this area.报告中提出的问题与“关心老人”组织在这方面正在做的工作有直接的关系。

15 cumbersome   

adj.笨重的，不便携带的

参考例句：

• Although the machine looks cumbersome,it is actually easy to use.尽管这台机器看上去很笨重，操作起来却很容易。
• The furniture is too cumbersome to move.家具太笨，搬起来很不方便。

16 pharmaceutical   

adj.药学的，药物的；药用的，药剂师的

参考例句：

• She has donated money to establish a pharmaceutical laboratory.她捐款成立了一个药剂实验室。
• We are engaged in a legal tussle with a large pharmaceutical company.我们正同一家大制药公司闹法律纠纷。

17 incentive   

n.刺激；动力；鼓励；诱因；动机

参考例句：

• Money is still a major incentive in most occupations.在许多职业中，钱仍是主要的鼓励因素。
• He hasn't much incentive to work hard.他没有努力工作的动机。

18 epidemic   

n.流行病；盛行；adj.流行性的，流传极广的

参考例句：

• That kind of epidemic disease has long been stamped out.那种传染病早已绝迹。
• The authorities tried to localise the epidemic.当局试图把流行病限制在局部范围。

19 bolster   

n.枕垫；v.支持，鼓励

参考例句：

• The high interest rates helped to bolster up the economy.高利率使经济更稳健。
• He tried to bolster up their morale.他尽力鼓舞他们的士气。

20 stigma   

n.耻辱，污名；(花的)柱头

参考例句：

• Being an unmarried mother used to carry a social stigma.做未婚母亲在社会上曾是不光彩的事。
• The stigma of losing weighed heavily on the team.失败的耻辱让整个队伍压力沉重。

21 proliferating   

激增( proliferate的现在分词 )； （迅速）繁殖； 增生； 扩散

参考例句：

• Computerized data bases are proliferating fast. 计算机化的数据库正在激增。
• Crown galls are cancerous growths composed of disorganized and proliferating plant cells. 冠瘿是无组织的正在不断增殖的植物细胞所组成的癌状物。

22 intimidating   

vt.恐吓，威胁( intimidate的现在分词)

参考例句：

• They were accused of intimidating people into voting for them. 他们被控胁迫选民投他们的票。
• This kind of questioning can be very intimidating to children. 这种问话的方式可能让孩子们非常害怕。

23 droplets   

n.小滴( droplet的名词复数 )

参考例句：

• Droplets of sweat were welling up on his forehead. 他额头上冒出了滴滴汗珠。 来自辞典例句
• In constrast, exhaled smoke contains relatively large water droplets and appears white. 相反，从人嘴里呼出的烟则包含相当大的水滴，所以呈白色。 来自辞典例句

24 bacterial   

a.细菌的

参考例句：

• Bacterial reproduction is accelerated in weightless space. 在失重的空间，细菌繁殖加快了。
• Brain lesions can be caused by bacterial infections. 大脑损伤可能由细菌感染引起。