The apparent recovery of Donald Trump since his Covid-19 diagnosis has focused attention on an experimental treatment he received.The US president was given three drugs, but leading US respiratory disease expert Anthony Fauci has said he is “strongly suspicious” that the 74-year-old’s recovery is attributable to an experimental cocktail called Regn-Cov2 that uses cloned antibodies taken from the blood of recovered Covid-19 patients to neutralise the virus.These drugs, known as monoclonal…