Professor Stephen Powis called on anyone who qualifies for a jab but has not yet received a first dose to book an appointment in the next few days.
The NHS is expecting a slowdown in UK vaccine supply for the whole of April, meaning medics will concentrate on delivering second doses, with fewer first appointments available.
NHS England has said no first appointments should be booked forpeople under the age of 50 unless they fall into a higher priority group, such as those who are clinically vulnerable.
It comes as the UK and European Union remained in talks to resolve a dispute over Covid-19 vaccine supplies.
Boris Johnson warned that a trade war over jabs would result in “considerable” and “long-term” damage.
Prof Powis said: “It is a testament to the careful planning and sheer hard work of staff that the NHS vaccination programme is continuing to protect people against coronavirus at a record pace.
“I was thrilled to get my first dose earlier this month, it was quick, painless and safe and it feels great knowing I’ve got protection against Covid-19 – so if you are eligible, do not delay, book a jab.”
Around seven in 10 people aged 50 to 54 have now had a first dose of a vaccine, according to NHS England.
Anybody aged 50 or over can book themselves in for a first dosebefore March 29 online using the national booking system for England.
People aged 18 and over who are clinically vulnerable should also book themselves in for a vaccine.
GPs will continue contacting eligible patients on their lists and offering vaccines to anyone who has not had one so far.
In a joint statement, the UK and EU said the two sides were seeking a “win-win” deal to increase supplies.
It came after the European Commission set out a tougher regime to stem supplies of jabs to nations faring better in the pandemic as the bloc’s states faced a third wave of cases.
Admitting it is a Covid-19 “hotspot”, the European Commission said on Wednesday it may not approve exports to nations with more advanced vaccine rollouts or where there is a better “epidemiological situation”.
The EU announced the move as it is embroiled in a row with AstraZeneca over supplies, but did not rule out Pfizer jabs being restricted to the UK if sufficient vaccines are not shipped to the bloc.
Member states were told to consider “reciprocity”, whether the destination country restricts its own vaccine exports, when authorising exports as the commission struck out against an alleged lack of British shipments.
Commission executive vice-president Valdis Dombrovskis denied the export authorisation mechanism was targeted at any one country but said 10 million jabs had moved from the EU to the UK since it introduced checks and that “zero doses” had returned from British plants.