A potential treatment for Covid-19 using plasma from recovered patients is to be trialled by doctors at London's Guy's and St Thomas' hospital.The first donations of the plasma have been collected and transfusions will begin in "the coming weeks", the hospital's Biomedical Research Centre said in a statement. It is hoped the potential treatment, known as convalescent plasma, will help patients whose bodies are not producing sufficient antibodies to fight the virus.The hospital says if the trials prove the treatment to be effective, NHS Blood and Transplant will begin a national programme to deliver up to 10,000 units of convalescent...