Cases of the virus stand at around 11,000 a day.
A professor who advises the government says a third wave of coronavirus is "definitely" under way in England.
Professor Adam Finn is a member of the Joint Committee on Vaccination and Immunisation (JCVI) and told the BBC that he was in no doubt about whether the country was experiencing a third wave of infections.
Finn told
BBC Radio 4's Today programme: "It's going up, perhaps we can be a little bit optimistic it's not going up any faster, but nevertheless it's going up - so this third wave is definitely under way.
"We can conclude that the race is firmly on between the vaccine programme, particularly getting older people's second doses done, and the Delta variant third wave."
The seven-day average of case numbers is currently 8,740, but on Friday more than 10,000 new cases were recorded.
The University of Bristol academic was also asked about the prospect of soon being able to give children over 12 the vaccine. However he said that this "wouldn't be appropriate right now," and that "it's adults that get sick, so vaccinating adults is clearly the priority."
Finn explained to the programme: "As far as vaccines are concerned the main emphasis everywhere at the moment is immunising adults - because it's adults that suffer predominantly from this infection.
"I think it's important that people don't imagine that immunising the young is going to have an immediate effect on the rise in numbers of cases.
"Although the vaccine is very effective, nevertheless it does take time to produce a response, and so young people will not be immediately immune when they walk out of the vaccine centre - it's going to take two to three weeks to begin to get some protection."
On Monday, Chris Whitty had said that children will likely need to be vaccinated in order to avoid any future disruption to their education, and a number of trials are taking place to licence the use of the jab on under-18s.
