英启动争议性疫苗试验
Controversial vaccine trials begin
为了加速研制出新冠疫苗，英国政府10月20日上午宣布，将开展一些有争议的疫苗试验，即“挑战试验”。
In a bid to speed up the race to find a vaccine for the novel coronavirus, the UK government announced Tuesday morning it will be launching some controversial vaccine trials known as challenge trials.
只有在18岁到30岁之间身体健康的人才会被选为志愿者。
Only people who are 18 to 30 years old and proven to be healthy will be taken as volunteers.
这些身体健康的年轻志愿者将接种新冠疫苗，然后将自己主动暴露在新冠病毒下，以便在受控环境中测试疫苗。这种做法在世界上尚属首次。
In a world first for COVID-19, young healthy volunteers will be vaccinated, then intentionally exposed to the potentially deadly virus in order to test vaccines in a controlled environment.
试验将在伦敦北部一家医院的隔离病房进行。
The experiment will take place in the quarantine ward of a North London hospital.
在吸入稀释剂量的新冠病毒后，试验参与者将被密切监测，科学家和医生将能更好地了解这一疾病以及新冠疫苗的效果。
After inhaling a diluted dose of the virus, the trial participants will be closely monitored, thus enabling scientists and doctors to better understand the disease and how a vaccine can fight it.
试验可能会在明年春天或夏天开始。
The trials will likely begin by next spring or summer.