The deputy chief medical officer for England has said he is "hopeful" the first coronavirus vaccine could be seen by Christmas. Speaking at a Downing Street press conference, Professor Jonathan Van-Tam said that the latest Pfizer and BioNTech trials represented a significant scientific breakthrough. However, he said that there was more to be done before it became available and that it would be for the independent regulator to clear it for use in the UK. "This is a very important scientific breakthrough. I am certain of that," he said. "I am hopeful because of all that, but not yet certain that we could begin to see some vaccine by Christmas."