Could this drug offer immediate protection from Covid-19?

When Donald Trump returned to the White House after a brief spell in hospital with Covid-19 last October he made a video attributing his rapid recovery to a drug he called ‘Regeneron’. ‘They call it a therapeutic drug, but to me it wasn’t therapeutic – it made me better,’ he said. ‘I call that a cure.’ Naturally, given that Trump had on a previous occasion appeared to advocate injecting humans with disinfectant, there was an element of scepticism on the part of many viewers. However, the drug he was talking about went on the receive emergency use authorisation in November from the US Food and Drug Administration. We now have