Every adult in England will be able to book their first Covid-19 vaccination from the end of this week, the head of the NHS has disclosed. Sir Simon Stevens said appointment slots would be opened to everyone aged 18 and above within a few days, to help the health service “finish the job” of vaccinating the entire adult population. He said it was vital that almost 6 million Britons aged 40 or over had their second dose of vaccine in the weeks between now and 19 July, the delayed date on which Boris Johnson hopes to ease restrictions in England on social mixing. It was due to be 21 June, until the date was put back four weeks on Monday night. “Today people aged 23 and 24 are able to book through the national booking service and I expect that by the end of this week we’ll be able to open up the national booking service to all adults aged 18 and above,” Stevens said in a speech to the NHS Confederation’s annual conference. He said 91% of people aged 50 and over in England had already had both vaccine doses, which confers the greatest possible protection against becoming seriously unwell with Covid. “But that still means that there are 1.3 million people for whom the opportunity stands, and for people in their 40s we’ve got 4.5 million people who have had one jab but not yet their second jab. “Given the decision announced last night to begin offering that now, after eight weeks rather than after 12, those second jabs for people in their 40s and above is a crucial part of what the next month needs to look like in the run-up to 19 July,” said Stevens, who is stepping down in late July as NHS England’s chief executive after more than seven years in post. Supply of the four vaccines now in use remained limited by their availability, he said. “Of course vaccine supply continues to be constrained, so we’re pacing ourselves at precisely the rate at which we’re getting the extra vaccine supply between now and 19 July.” Stevens also said: Two vaccine doses “are as effective, if not more so, in preventing hospitalisations for the more transmissible Delta [Indian] variant than for the Alpha [Kent] variant”. As a result the NHS was “in a much better position now than we were this time last year, when we had an equivalently modest number of hospital Covid patients across the country, precisely because of the protective wall that vaccinations provide”. 1% of hospital beds in England are occupied by people with Covid. The vaccination programme means that patients in hospital now with Covid are generally younger than in the second wave in January that left the NHS struggling to cope. “The age distribution has really flipped as a result of vaccination. Whereas back in January it was 60/40 – 60% were occupied by people over 65 and 40% [by those] under 65 – now it’s flipped to 70/30. So it’s about 30% occupied by people aged 65 and over, [and] 70% are younger people whose prospects are much greater,” Stevens said.