研究发现特定剂量的黄热病疫苗有助预防疾病

Partial-dose Yellow Fever Vaccine¹ Effective in Emergencies

A new study suggests that partial doses of the yellow fever vaccine can help protect communities against the disease.

The study was published in the New England Journal of Medicine. It found that individuals given a one-fifth dose of yellow fever vaccine developed enough antibodies to protect them against infection.

Erin Staples² was one of the writers of a report on the study. She says this is good news in places where the vaccine is in short supply.

"That was the encouraging thing, that this can be done as a potential way — when there's supply limitations on the vaccine — to help potentially control an outbreak."

Staples works for the Centers for Disease Control and Prevention (CDC), which is an agency of the United States government.

Yellow fever is a serious problem in parts of Africa, as well as Central and South America. People get the disease from infected mosquitoes. The term “yellow” in the name describes the yellow coloring of some patients’ skin.

The World Health Organization says a small number of patients develop severe health problems and about half of them die within seven to 10 days.

Staples noted³ that in the Democratic Republic of the Congo, health workers had to use partial doses of the yellow fever vaccine in 2016. At that time, the vaccine was in short supply.

The World Health Organization suggested a one-fifth dose based on some experiments performed in Brazil. Staples said many experts wondered if a partial dosage would be effective against the disease. She noted that nearly 8 million people were targeted for vaccination⁴ in the city of Kinshasa.

"It worked in small cohorts, in a well-controlled clinical trial situation. But when you go to do this large scale in the field, does it work?"

The partial amount proved effective. Ninety-eight percent of people tested had protective antibodies to the virus one month after being vaccinated⁶.

In Brazil, more than 350 people have become sick with yellow fever since late last year. Vaccine supplies remain in short supply.

Health officials have launched what they are calling the largest-ever partial-dose mass vaccination campaign. The goal is to vaccinate⁵ nearly 24 million people. Each person is being given a one-fifth dose of the yellow fever vaccine.

Staples says the new research offers hope.

"I think that's very encouraging for the short term, immediate⁷ control. We still need some information about how long immunity⁸ will last."

A full dose of yellow fever vaccine provides lifelong protection against the disease. Researchers will continue to study how long people who received partial doses are protected.

I’m Jonathan Evans.

Words in this Story

antibody – n. a substance produced by the body to fight disease

dose – n. the amount of a medicine, drug, or vitamin that is taken at one time

encouraging – adj. causing a hopeful feeling

outbreak – n. a sudden increase in the number of cases of a disease

cohort – n. a friend or someone you know

clinical – adj. related to a place where medical treatment is provided

scale – n. the size of something, especially when compared to something else

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 staples   

n.（某国的）主要产品( staple的名词复数 )；钉书钉；U 形钉；主要部份v.用钉书钉钉住( staple的第三人称单数 )

参考例句：

• The anvil onto which the staples are pressed was not assemble correctly. 订书机上的铁砧安装错位。 来自辞典例句
• I'm trying to make an analysis of the staples of his talk. 我在试行分析他的谈话的要旨。 来自辞典例句

3 noted   

adj.著名的，知名的

参考例句：

• The local hotel is noted for its good table.当地的那家酒店以餐食精美而著称。
• Jim is noted for arriving late for work.吉姆上班迟到出了名。

4 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。

5 vaccinate   

vt.给…接种疫苗；种牛痘

参考例句：

• Local health officials then can plan the best times to vaccinate people.这样，当地的卫生官员就可以安排最佳时间给人们接种疫苗。
• Doctors vaccinate us so that we do not catch smallpox.医生给我们打预防针使我们不会得天花。

6 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？

7 immediate   

adj.立即的；直接的，最接近的；紧靠的

参考例句：

• His immediate neighbours felt it their duty to call.他的近邻认为他们有责任去拜访。
• We declared ourselves for the immediate convocation of the meeting.我们主张立即召开这个会议。

8 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。