A snag in the supply of Covid-19 jabs is behind the drop in the number of first doses administered on Sunday, Downing Street has said. No10 stressed the Government was not stockpiling vaccines and they were being rushed out to hospitals, GP hubs and mass vaccination centres as quickly as possible. “As ministers have said on a number of occasions it is supply that is the limiting factor at present but as you have seen throughout December and through January we have ramped up the vaccination programme and you will have seen yesterday that we hit four million dose mark.”