Does mass testing work?

摘要

IT LOOKS likely that some countries will soon be able to vaccinate at least some people against the coronavirus (see page 7), but until vaccines are widely available, mass testing is seen as a route back to normal life. For example, UK prime minister Boris Johnson announced on 23 November that daily coronavirus tests will be given to people who have come into contact with anyone who has tested positive for the coronavirus, in an attempt to limit the number of days they have to self-isolate. The measure will be trialled in Liverpool, which began mass testing earlier this month.