The UK government has said a further 6,238 lab-confirmed cases of coronavirus have been recorded as of 9am on Friday, the highest single-day figure since 25 March.

A further 11 people had died within 28 days of testing positive for Covid-19 as of Friday, bringing the UK total to 127,823.

Separate figures published by the Office for National Statistics show there have now been 153,000 deaths registered in the UK where Covid-19 was mentioned on the death certificate.

Government data up to 3 June also shows that of the 66,749,638 vaccinations given in the UK so far, 39,949,694 were first doses - a rise of 191,266 on the previous day.

Some 26,799,944 were second doses, an increase of 377,641.

It comes as Britain's medicines regulator said it has approved the Covid-19 vaccine developed by Pfizer/BioNTech for use on 12 to 15-year-olds, following similar clearances in the US and the EU.

The regulator said it would now be up to the country's Joint Committee on Vaccination and Immunisation (JCVI) to decide whether to go ahead and inoculate this age group as part of Britain's vaccination roll-out plan.

Children aged 12-15 are already receiving the Pfizer shot in the United States, while France and Germany are planning to start offering it to that age group this month.

Britain's Health and Social Care department said it would provide an update once the JCVI had made its decision.

The chief executive of the UK Medicines and Healthcare products Regulatory Agency June Raine said in a statement that her agency had carefully reviewed the clinical trial data in children aged 12 to 15 years old.

"(We) have concluded that the Pfizer/BioNTech Covid-19 vaccine is safe and effective in this age group and that the benefits of this vaccine outweigh any risk," she said.

However, giving vaccines to younger people in affluent countries while many parts of the world await doses for older and more vulnerable people has raised concerns.

The World Health Organization has urged rich countries to give shots to the COVAX scheme instead.

Explainer: Countries vaccinating children against Covid-19

Britain was the first Western country to start a mass immunisation drive, in December.

The government said yesterday that over half of adults had now received both doses of inoculation, mainly the Pfizer/BioNTech or AstraZeneca.

More than three-quarters of adults have received at least a single dose.

Switzerland approves Pfizer/BioNTech vaccine for 12-15 year olds

Switzerland has approved vaccinating 12-to-15-year-old children with the Covid-19 shot from Pfizer and BioNTEch, ahead of the country's plan to start inoculating younger people starting as early as July.

"Swiss medic has carefully examined the indication-extension application submitted by Pfizer," the regulator said in a statement, after giving the shot temporary ordinary authorisation for 12- to 15-year-olds.

US drugmaker Moderna is also gearing up to seek approval for children for its vaccine after study data showed it was safe and effective.

In Switzerland, officials have said they hope to vaccinate 12- to 15-year-olds starting this summer, to be ready for the 2021/2022 school year and to help reduce a potential transmission source for the virus heading into the coming winter.

"The more people are vaccinated, and children are part of this, the less virus will circulate and the less danger there will be for risk groups," the Swiss Federal Health Ministry told Reuters in response to questions about its strategy for children.