Under-30s are to be offered their coronavirus vaccine jabs this week, the Health Secretary has confirmed.

Here the PA news agency looks at how the vaccine rollout is progressing.

– What is the current eligibility criteria in the UK?

All those aged 30 and over are currently being offered the vaccine in England and Scotland, while in Wales and Northern Ireland this is everyone aged 18 and over.

Matt Hancock said people aged under 30 in England would be invited to book their first doses this coming week.

– When are all adults due to be offered the vaccine?

The Government has said it intends to offer a first dose of a vaccine to all adults by the end of July, and both doses to everyone aged 50 and over by June 21.

Mr Hancock said he expected “around three-fifths” of all adults to have been fully vaccinated by June 21.

– How many vaccinations have been given so far?

According to the latest figures, a total of 67,284,864 vaccinations have been given in the UK up to June 4, including 40,124,229 first doses and 27,160,635 second doses.

This equates to more than three quarters of adults in the UK having had a first dose, and more than half having had both doses.

– I’ve heard some healthy people in their 20s have already received their first dose. Why?

The Royal College of General Practitioners (RCGP) has said that in some areas, GPs have vaccinated all those eligible and so are moving to the next cohort.

Dr Steve Mowle, spokesman and a GP in south London, said: “At some sites, it is likely GPs have finished vaccinating all eligible patients including those aged 30 and over and are now moving on to the next age cohort.

“This only shows how successful the Covid vaccination programme has been so far, and the incredible and pivotal work of GPs and teams in delivering the programme so efficiently.”

– Could there be other reasons?

Yes. Guidance from the British Medical Association (BMA), a trade union and professional body for doctors, says that surplus vaccine supply may occur and that the overriding principle is to avoid wastage.

“Sites should have reserve lists that they can use to make every effort to invite patients or healthcare professionals to make full use of any unused vaccines rather than have any go to waste,” the guidance states.

“If necessary, remaining doses can be given outside the current cohorts if there is no one else available.”

– How are healthy people in their 20s booking their jabs?

In cases where GPs have vaccinated all over 30s and are moving to the next cohort, people who are now eligible will be contacted by the site.

Elsewhere, other vaccine centres are holding drop-in centres where anyone aged over 25 – and in some cases 18 – can turn up on the day to be vaccinated without an appointment.

– What jabs are being offered to younger cohorts?

Official advice from the Joint Committee on Vaccination and Immunisation says that under-40s should be offered alternatives to the Oxford/AstraZeneca vaccine.

The UK’s advisory body made the precautionary change because of evidence the vaccine may be linked to very rare blood clots, meaning the Moderna and Pfizer jabs are being favoured for this age group.