تجارب جامعة اكسفورد بشان تطوير واكتشاف لقاح لفيروس كورونا
More than 1,000 volunteers are now part of the Oxford vaccine study. Half will get ChAdOx1 nCoV-19, as the vaccine is called, and the rest a control vaccine which protects against meningitis. The trial is "blinded" so that the researchers and the volunteers won't know which jab they are getting.
The use of a real vaccine as a control, which may result in the odd sore arm, means volunteers really won't know whether they have got the real thing. That's important, as all of them will need to keep a daily health diary for up to four weeks, and come back for several blood tests.