On Thursday 14 October, the European Medicines Agency (EMA) announced that it had begun evaluating a new candidate treatment for Covid-19 developed by the pharmaceutical company AstraZeneca. This candidate treatment, called Evusheld - or AZD7442 - is a combination of two monoclonal antibodies: tixagevimab and cilgavimab. The EMA is currently evaluating data from laboratory and animal studies. It says that it “will evaluate more data on the quality, safety and effectiveness of the medicine...