VOA标准英语2011--Rotavirus Immunization Protects People W

Rotavirus Immunization Protects People Who Don't Get Vaccine¹

Rotavirus causes severe diarrhea that kills more than a half-million people each year, mostly very young children. A recently-introduced vaccine has proved to be very effective and has shown some unexpected benefits, extending protection beyond the children who received the vaccinations³.
Rotavirus fatalities⁴ are rare in the United States, but the disease does send tens of thousands of children to the hospital each year.
Nationwide vaccinations began in the U.S. in 2006, and now researchers are evaluating the results.
They already know that the vaccine is effective, with diarrhea-related hospitalizations down 50 percent just two years after the immunization program started. But researcher Ben A. Lopman, with the U.S. Centers for Disease Control and Prevention, says the protection went far beyond the children who actually got vaccinated⁵.
"The vaccine program also was providing indirect protection against hospitalizations in older children, and adults and in the elderly. [There] were fewer hospitalizations in 2008 - over 10,000 fewer hospitalizations in these older age groups - than in previous years."
This indirect protection - sometimes called herd⁶ immunity⁷ - occurs when there are fewer people to pass around an infection, as Lopman explains.
"The idea here is that by vaccinating⁸ young children, you stop them from transmitting infection to their older siblings⁹, their parents, their grandparents, etc., because those children themselves are not becoming infected because they've been vaccinated."
There's another surprise here - that older children and adults were getting rotavirus infections in significant numbers. While the vaccine is only recommended for young children, Lopman says his study suggests that doctors should be aware that patients with rotavirus symptoms may be infected, regardless of age.
Although this study was done in the United States, rotavirus is a much more serious problem in low- and middle-income countries, and the vaccine hasn’t been as effective in those areas. So Lopman says he can't say if his findings would apply there.
"The kinetics of rotavirus transmission are very different in low-income settings, where there seems to be just much more rotavirus around. So it's not clear at this stage whether these indirect benefits would be afforded in low-income settings or not."
In a commentary published with the research paper, a senior official of the U.S. National Institutes of Health, Roger I. Glass, director of the NIH Fogarty International Center, says more research is needed to measure the effectiveness of a rotavirus vaccination² program conducted where the disease is a much more serious threat. But the official writes that Lopman's study suggests the indirect protection benefit should be considered in assessing the value of a vaccination program.
The research study by Ben A. Lopman and colleagues is published online by the Journal of Infectious Diseases.

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 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。

3 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》

4 fatalities   

n.恶性事故( fatality的名词复数 )；死亡；致命性；命运

参考例句：

• Several people were injured, but there were no fatalities. 有几个人受伤，但没有人死亡。
• The accident resulted in fatalities. 那宗意外道致多人死亡。 来自《简明英汉词典》

5 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？

6 herd   

n.兽群，牧群；vt.使集中，把…赶在一起

参考例句：

• She drove the herd of cattle through the wilderness.她赶着牛群穿过荒野。
• He had no opinions of his own but simply follow the herd.他从无主见，只是人云亦云。

7 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。

8 vaccinating   

给…接种疫苗( vaccinate的现在分词 )； 注射疫苗，接种疫苗

参考例句：

• At first blush, vaccinating the wolves against rabies seems a simple solution. 乍一看来，为狼群注射防狂犬病疫苗是一种简单的办法。
• Also vaccinating children against misers (measles) has saved many lives. 还有，给儿童进行疫苗接种防止麻疹也挽救了许多生命。

9 siblings   

n.兄弟，姐妹( sibling的名词复数 )

参考例句：

• A triplet sleeps amongst its two siblings. 一个三胞胎睡在其两个同胞之间。 来自《简明英汉词典》
• She has no way of tracking the donor or her half-siblings down. 她没办法找到那个捐精者或她的兄弟姐妹。 来自时文部分